1. Which of the following quantities is a vector quantity?
ⓐ. Speed
ⓑ. Distance
ⓒ. Velocity
ⓓ. Mass
Explanation: Velocity is a vector quantity because it has both magnitude and direction, unlike speed, which is a scalar quantity and only has magnitude. Distance and mass are also scalar quantities.
2. Which of the following represents the correct formula for displacement in two-dimensional motion?
ⓐ. \(s = ut + \frac{1}{2}at^2\)
ⓑ. \(\vec{r} = \vec{r_0} + \vec{v}t + \frac{1}{2}\vec{a}t^2\)
ⓒ. \(v = u + at\)
ⓓ. \(F = ma\)
Explanation: This formula represents the position vector \(\vec{r}\) in two-dimensional motion, where \(\vec{r_0}\) is the initial position vector, \(\vec{v}\) is the initial velocity vector, \(\vec{a}\) is the acceleration vector, and \(t\) is the time.
3. What is the trajectory of a projectile in a uniform gravitational field, assuming no air resistance?
ⓐ. Circular
ⓑ. Parabolic
ⓒ. Elliptical
ⓓ. Hyperbolic
Explanation: The trajectory of a projectile under the influence of gravity, without air resistance, is a parabola. This is because the horizontal and vertical motions are independent of each other, with the vertical motion being uniformly accelerated due to gravity.
4. In projectile motion, what is the horizontal component of the velocity of the projectile at the highest point of its trajectory?
ⓐ. Zero
ⓑ. Maximum
ⓒ. Minimum
ⓓ. Equal to the initial horizontal component
Explanation: The horizontal component of velocity remains constant throughout the projectile’s motion because there are no horizontal forces acting on the projectile (assuming no air resistance).
5. What is the angle of projection for maximum horizontal range in projectile motion?
ⓐ. 30 degrees
ⓑ. 45 degrees
ⓒ. 60 degrees
ⓓ. 90 degrees
Explanation: For maximum horizontal range, the angle of projection should be 45 degrees. This angle provides the optimal balance between the horizontal and vertical components of the initial velocity.
6. Which of the following quantities remains constant during the projectile motion of an object?
ⓐ. Vertical component of velocity
ⓑ. Horizontal component of velocity
ⓒ. Vertical displacement
ⓓ. Horizontal displacement
Explanation: In projectile motion, the horizontal component of velocity remains constant if air resistance is neglected because there are no horizontal forces acting on the object.
7. If a projectile is launched at an angle θ with initial velocity \(v_0\), what is the time of flight of the projectile?
ⓐ. \(\frac{2v_0 \sin\theta}{g}\)
ⓑ. \(\frac{v_0 \sin\theta}{g}\)
ⓒ. \(\frac{v_0 \cos\theta}{g}\)
ⓓ. \(\frac{2v_0 \cos\theta}{g}\)
Explanation: The time of flight for a projectile launched at an angle θ with initial velocity \(v_0\) is given by \(T = \frac{2v_0 \sin\theta}{g}\), where \(g\) is the acceleration due to gravity. This formula considers the total time the projectile spends in the air.
8. Which component of acceleration remains constant in projectile motion?
ⓐ. Horizontal acceleration
ⓑ. Vertical acceleration
ⓒ. Both horizontal and vertical acceleration
ⓓ. Neither horizontal nor vertical acceleration
Explanation: In projectile motion, the vertical acceleration remains constant and equal to \(g\), the acceleration due to gravity. The horizontal acceleration is zero in the absence of air resistance.
9. In uniform circular motion, what is the direction of the centripetal acceleration?
ⓐ. Tangent to the circle
ⓑ. Away from the center of the circle
ⓒ. Toward the center of the circle
ⓓ. Perpendicular to the plane of the circle
Explanation: In uniform circular motion, the centripetal acceleration always points toward the center of the circle, keeping the object in circular motion.
10. If an object is moving in a circle of radius \(r\) with a constant speed \(v\), what is the magnitude of its centripetal acceleration?
ⓐ. \(\frac{v^2}{r}\)
ⓑ. \(\frac{v}{r}\)
ⓒ. \(\frac{r}{v}\)
ⓓ. \(vr\)
Explanation: The magnitude of the centripetal acceleration \(a_c\) for an object moving in a circle of radius \(r\) with a constant speed \(v\) is given by \(a_c = \frac{v^2}{r}\). This acceleration is directed toward the center of the circle.
11. What is the difference between scalar and vector quantities?
ⓐ. Scalar quantities have only magnitude, while vector quantities have only direction.
ⓑ. Scalar quantities have only direction, while vector quantities have only magnitude.
ⓒ. Scalar quantities have both magnitude and direction, while vector quantities have only magnitude.
ⓓ. Scalar quantities have only magnitude, while vector quantities have both magnitude and direction.
Explanation: Scalar quantities are defined by their magnitude alone, such as distance and speed, while vector quantities have both magnitude and direction, such as displacement and velocity.
12. Which of the following is an example of a vector quantity?
ⓐ. Time
ⓑ. Temperature
ⓒ. Force
ⓓ. Distance
Explanation: Force is a vector quantity because it has both magnitude and direction. Time and temperature are scalar quantities with only magnitude, and distance is also a scalar quantity.
13. What is the correct representation of a vector quantity?
ⓐ. A numerical value only
ⓑ. A direction only
ⓒ. A numerical value with a unit
ⓓ. A numerical value with a direction and a unit
Explanation: A vector quantity is represented by a numerical value (magnitude), a direction, and a unit of measurement, for example, 5 meters per second north.
14. Which of the following pairs represents perpendicular components in two-dimensional motion?
ⓐ. Velocity and speed
ⓑ. Distance and displacement
ⓒ. Horizontal and vertical components of velocity
ⓓ. Mass and weight
Explanation: In two-dimensional motion, the horizontal and vertical components of velocity are perpendicular to each other. They can be independently analyzed using vector addition.
15. How is the resultant vector of two vectors A and B determined graphically?
ⓐ. By adding the magnitudes of A and B
ⓑ. By subtracting the magnitudes of A and B
ⓒ. By placing the tail of B at the head of A and drawing a vector from the tail of A to the head of B
ⓓ. By placing the head of B at the tail of A and drawing a vector from the tail of B to the head of A
Explanation: The graphical method for finding the resultant of two vectors involves placing the tail of the second vector at the head of the first vector and then drawing the resultant vector from the tail of the first vector to the head of the second vector.
16. In vector addition, what is the resultant of two vectors of equal magnitude but opposite directions?
ⓐ. A vector with double the magnitude
ⓑ. A vector with half the magnitude
ⓒ. A zero vector
ⓓ. A vector perpendicular to the original vectors
Explanation: When two vectors of equal magnitude but opposite directions are added, their effects cancel each other out, resulting in a zero vector (no magnitude and no direction).
17. What is the term used to describe the path of an object in motion in a plane?
ⓐ. Displacement
ⓑ. Velocity
ⓒ. Trajectory
ⓓ. Acceleration
Explanation: The trajectory is the path that an object follows as it moves through space. In the context of motion in a plane, it is the two-dimensional path traced by the object.
18. What does the term “relative velocity” refer to in the context of motion in a plane?
ⓐ. The velocity of an object relative to the ground
ⓑ. The velocity of an object relative to another moving object
ⓒ. The change in velocity of an object over time
ⓓ. The velocity of an object in a straight line
Explanation: Relative velocity is the velocity of one object as observed from another moving object. It describes how fast one object is moving in relation to another.
19. If an object moves in a plane with a constant velocity, what is the shape of its trajectory?
ⓐ. Circular
ⓑ. Parabolic
ⓒ. Linear
ⓓ. Elliptical
Explanation: If an object moves with constant velocity in a plane, its trajectory is a straight line (linear). The object covers equal distances in equal time intervals in a specified direction.
20. In the context of vector operations, what is the result of multiplying a vector by a scalar?
ⓐ. A vector with the same direction and modified magnitude
ⓑ. A scalar quantity with modified magnitude
ⓒ. A vector with a different direction and modified magnitude
ⓓ. A zero vector
Explanation: When a vector is multiplied by a scalar, the result is a vector whose magnitude is scaled by the scalar, but the direction remains the same as the original vector.
21. What is rectilinear motion?
ⓐ. Motion in a circular path
ⓑ. Motion in a curved path
ⓒ. Motion in a straight line
ⓓ. Motion in a random path
Explanation: Rectilinear motion is the motion of an object along a straight line. This type of motion is characterized by the object moving in a single dimension without changing its direction.
22. Which of the following is an example of rectilinear motion?
ⓐ. A car moving on a straight road
ⓑ. A satellite orbiting the Earth
ⓒ. A ball thrown in a parabolic path
ⓓ. A pendulum swinging
Explanation: A car moving on a straight road is an example of rectilinear motion, where the car moves in a straight line without deviating from its path.
23. What is the formula for average velocity in rectilinear motion?
ⓐ. \( v = u + at \)
ⓑ. \( v = \frac{d}{t} \)
ⓒ. \( v = \frac{2d}{t} \)
ⓓ. \( v = u – at \)
Explanation: In rectilinear motion, average velocity \(v\) is calculated as the total displacement \(d\) divided by the total time \(t\) taken. This formula applies when the motion is uniform or the average is considered over a period.
24. If a particle moves with uniform velocity in rectilinear motion, what can be said about its acceleration?
ⓐ. Acceleration is increasing
ⓑ. Acceleration is decreasing
ⓒ. Acceleration is zero
ⓓ. Acceleration is constant but non-zero
Explanation: If a particle moves with uniform velocity, it means that there is no change in its velocity. Therefore, its acceleration, which is the rate of change of velocity, is zero.
25. Which of the following represents the equation of motion for uniformly accelerated rectilinear motion?
ⓐ. \( s = ut + \frac{1}{2}at^2 \)
ⓑ. \( s = vt + \frac{1}{2}at^2 \)
ⓒ. \( s = ut – \frac{1}{2}at^2 \)
ⓓ. \( s = vt – \frac{1}{2}at^2 \)
Explanation: The equation \( s = ut + \frac{1}{2}at^2 \) represents the displacement \(s\) in uniformly accelerated rectilinear motion, where \(u\) is the initial velocity, \(a\) is the acceleration, and \(t\) is the time.
26. What is the term used to describe the change in velocity per unit time?
ⓐ. Speed
ⓑ. Acceleration
ⓒ. Displacement
ⓓ. Distance
Explanation: Acceleration is the term used to describe the change in velocity per unit time. It is a vector quantity and can be positive (increasing velocity) or negative (decreasing velocity).
27. In rectilinear motion, what does the area under a velocity-time graph represent?
ⓐ. Velocity
ⓑ. Acceleration
ⓒ. Displacement
ⓓ. Speed
Explanation: The area under a velocity-time graph in rectilinear motion represents the displacement of the object. The graph visually depicts how the velocity changes over time, and the area calculates the total displacement.
28. What is the difference between distance and displacement in rectilinear motion?
ⓐ. Distance is a vector quantity, and displacement is a scalar quantity.
ⓑ. Distance is the shortest path between two points, and displacement is the actual path traveled.
ⓒ. Distance is always equal to displacement.
ⓓ. Distance is the actual path traveled, and displacement is the shortest path between two points.
Explanation: Distance is a scalar quantity that represents the total path traveled by an object, while displacement is a vector quantity that represents the shortest path between the initial and final positions of the object.
29. If an object covers equal distances in equal intervals of time, what type of motion does it exhibit?
ⓐ. Uniform acceleration
ⓑ. Non-uniform acceleration
ⓒ. Uniform motion
ⓓ. Non-uniform motion
Explanation: If an object covers equal distances in equal intervals of time, it exhibits uniform motion. This indicates that the object’s speed is constant throughout its motion.
30. An object starts from rest and moves with a constant acceleration of 2 m/s². What will be its velocity after 5 seconds?
ⓐ. 5 m/s
ⓑ. 10 m/s
ⓒ. 15 m/s
ⓓ. 20 m/s
Explanation: Using the equation of motion \( v = u + at \), where \(u\) is the initial velocity (0 m/s), \(a\) is the acceleration (2 m/s²), and \(t\) is the time (5 seconds), we get \( v = 0 + (2 \times 5) = 10 \) m/s. So, the velocity after 5 seconds is 10 m/s.
31. What is curvilinear motion?
ⓐ. Motion in a straight line
ⓑ. Motion along a circular path
ⓒ. Motion along a curved path
ⓓ. Random motion
Explanation: Curvilinear motion refers to the motion of an object along a curved path. It can be in any plane and is characterized by continuous change in direction.
32. Which of the following is an example of curvilinear motion?
ⓐ. A car moving on a straight road
ⓑ. A stone thrown horizontally from a height
ⓒ. A pendulum swinging back and forth
ⓓ. A satellite orbiting the Earth
Explanation: A stone thrown horizontally from a height follows a parabolic trajectory, which is an example of curvilinear motion due to the influence of gravity causing the path to curve.
33. In curvilinear motion, what is the term used to describe the rate of change of velocity along the curve?
ⓐ. Speed
ⓑ. Linear acceleration
ⓒ. Angular acceleration
ⓓ. Tangential acceleration
Explanation: Tangential acceleration refers to the rate of change of the velocity along the path of the curve. It is responsible for changing the speed of the object as it moves along the curved path.
34. Which component of acceleration is responsible for changing the direction of velocity in curvilinear motion?
ⓐ. Radial acceleration
ⓑ. Tangential acceleration
ⓒ. Linear acceleration
ⓓ. Uniform acceleration
Explanation: Radial acceleration (also known as centripetal acceleration) is responsible for changing the direction of velocity in curvilinear motion. It acts towards the center of the curvature, causing the object to change its direction.
35. What shape does the path of a projectile follow under the influence of gravity?
ⓐ. Linear
ⓑ. Circular
ⓒ. Elliptical
ⓓ. Parabolic
Explanation: The path of a projectile under the influence of gravity follows a parabolic trajectory. This is a result of the constant acceleration due to gravity acting downward while the horizontal component of motion remains constant.
36. In uniform circular motion, what remains constant?
ⓐ. Speed
ⓑ. Velocity
ⓒ. Acceleration
ⓓ. Displacement
Explanation: In uniform circular motion, the speed of the object remains constant, while its velocity changes continuously due to the change in direction. The centripetal acceleration keeps the object moving in a circular path.
37. What type of force is required to maintain an object in circular motion?
ⓐ. Frictional force
ⓑ. Centripetal force
ⓒ. Gravitational force
ⓓ. Electromagnetic force
Explanation: Centripetal force is required to maintain an object in circular motion. This force acts towards the center of the circle, causing the object to change direction continuously and move along a circular path.
38. Which of the following best describes non-uniform circular motion?
ⓐ. Motion along a straight path at a constant speed
ⓑ. Motion along a curved path with a constant speed
ⓒ. Motion along a curved path with changing speed
ⓓ. Motion along a straight path with changing speed
Explanation: Non-uniform circular motion occurs when an object moves along a curved path with changing speed. Both the magnitude and direction of the velocity change in this type of motion.
39. What is the term used to describe the angle swept by the radius vector per unit time in circular motion?
ⓐ. Linear velocity
ⓑ. Angular velocity
ⓒ. Tangential velocity
ⓓ. Radial velocity
Explanation: Angular velocity is the term used to describe the angle swept by the radius vector per unit time in circular motion. It measures how quickly an object rotates or revolves around a central point.
40. If an object moves along a circular path with a radius \( r \) and a constant speed \( v \), what is the magnitude of its centripetal acceleration?
ⓐ. \( \frac{v}{r} \)
ⓑ. \( \frac{v^2}{r} \)
ⓒ. \( \frac{r}{v^2} \)
ⓓ. \( \frac{r^2}{v} \)
Explanation: The magnitude of centripetal acceleration \( a_c \) for an object moving with a constant speed \( v \) along a circular path with radius \( r \) is given by \( a_c = \frac{v^2}{r} \). This acceleration acts towards the center of the circle, keeping the object in circular motion.
41. Why is it important to study motion in two dimensions?
ⓐ. To understand linear motion only
ⓑ. To predict the behavior of objects in a straight line
ⓒ. To analyze complex motions like projectiles and circular motion
ⓓ. To simplify the study of motion in one dimension
Explanation: Studying motion in two dimensions allows us to understand and analyze more complex motions, such as projectile motion and circular motion, which cannot be adequately described by one-dimensional analysis alone.
42. Which of the following real-life applications involve motion in two dimensions?
ⓐ. A car driving on a straight road
ⓑ. A ball thrown in the air
ⓒ. An elevator moving up and down
ⓓ. A train on a straight track
Explanation: A ball thrown in the air follows a curved path and experiences both horizontal and vertical motion simultaneously, making it a clear example of two-dimensional motion.
43. How does studying motion in two dimensions help in understanding projectile motion?
ⓐ. It eliminates the need to consider gravity
ⓑ. It allows for the separation of horizontal and vertical components of motion
ⓒ. It simplifies motion to a single dimension
ⓓ. It neglects air resistance
Explanation: Studying motion in two dimensions helps us to separate and analyze the horizontal and vertical components of projectile motion independently, making it easier to predict the path of the projectile.
44. What is a key benefit of understanding motion in two dimensions for engineers?
ⓐ. It is only useful for theoretical physics
ⓑ. It has no practical applications
ⓒ. It helps in designing trajectories for projectiles and vehicles
ⓓ. It simplifies the study of statics
Explanation: Understanding motion in two dimensions is crucial for engineers when designing trajectories for projectiles, vehicles, and other objects, ensuring accurate predictions and safe, efficient designs.
45. In which field is the study of two-dimensional motion particularly important?
ⓐ. Medicine
ⓑ. Computer science
ⓒ. Astronomy
ⓓ. History
Explanation: The study of two-dimensional motion is particularly important in astronomy for analyzing the orbits of planets, moons, and other celestial bodies, which often move in elliptical or curved paths.
46. How does studying motion in two dimensions aid in sports science?
ⓐ. It is not relevant to sports
ⓑ. It helps athletes run faster
ⓒ. It allows for the analysis of trajectories in sports like basketball and soccer
ⓓ. It only applies to static exercises
Explanation: In sports science, understanding motion in two dimensions is vital for analyzing and optimizing the trajectories of balls in sports like basketball, soccer, and tennis, improving performance and strategy.
47. What is a common method used to analyze two-dimensional motion?
ⓐ. Ignoring one dimension
ⓑ. Using vector decomposition
ⓒ. Assuming uniform motion
ⓓ. Neglecting air resistance
Explanation: A common method to analyze two-dimensional motion is vector decomposition, where the motion is broken down into perpendicular components (usually horizontal and vertical), making it easier to study and solve problems.
48. Which of the following describes the motion of a car turning around a curve on a flat road?
ⓐ. One-dimensional motion
ⓑ. Projectile motion
ⓒ. Uniform rectilinear motion
ⓓ. Two-dimensional motion
Explanation: A car turning around a curve on a flat road involves both forward motion and a change in direction, making it an example of two-dimensional motion.
49. What role does studying motion in two dimensions play in aviation?
ⓐ. It is irrelevant to flight paths
ⓑ. It helps in understanding fuel consumption
ⓒ. It assists in plotting flight paths and understanding takeoff and landing dynamics
ⓓ. It only applies to helicopter flight
Explanation: In aviation, studying motion in two dimensions is essential for plotting flight paths and understanding the dynamics of takeoff, landing, and maneuvering in the air.
50. Why is the study of motion in two dimensions crucial for satellite technology?
ⓐ. It simplifies the technology used
ⓑ. It is not important for satellites
ⓒ. It enables the calculation of precise orbits and trajectories
ⓓ. It reduces the cost of satellite launches
Explanation: For satellite technology, understanding motion in two dimensions is crucial for calculating precise orbits and trajectories, ensuring that satellites are placed and maintained in their correct positions for optimal functionality.
51. What is a scalar quantity?
ⓐ. A quantity with only magnitude
ⓑ. A quantity with both magnitude and direction
ⓒ. A quantity with only direction
ⓓ. A quantity with no magnitude or direction
Explanation: A scalar quantity is defined by its magnitude alone and does not include any information about direction. Examples include mass, temperature, and time.
52. Which of the following is an example of a vector quantity?
ⓐ. Speed
ⓑ. Time
ⓒ. Velocity
ⓓ. Temperature
Explanation: A vector quantity has both magnitude and direction. Velocity is a vector because it specifies the speed of an object as well as the direction of its motion.
53. Which of the following operations can be performed on scalar quantities?
ⓐ. Addition and subtraction
ⓑ. Addition, subtraction, and vector multiplication
ⓒ. Only multiplication
ⓓ. Vector addition and vector subtraction
Explanation: Scalar quantities can be added, subtracted, multiplied, and divided using standard arithmetic operations since they have only magnitude.
54. What defines a vector quantity?
ⓐ. Only magnitude
ⓑ. Only direction
ⓒ. Magnitude and direction
ⓓ. Neither magnitude nor direction
Explanation: A vector quantity is characterized by having both a magnitude and a direction, making it essential for representing quantities like force, velocity, and displacement.
55. Which of the following is a scalar quantity?
ⓐ. Displacement
ⓑ. Force
ⓒ. Work
ⓓ. Acceleration
Explanation: Work is a scalar quantity because it only involves magnitude (the amount of energy transferred) and does not depend on direction.
56. How is a vector typically represented in diagrams?
ⓐ. By a single point
ⓑ. By a straight line without an arrow
ⓒ. By a straight line with an arrow
ⓓ. By a dotted line
Explanation: Vectors are represented by arrows in diagrams, where the length of the arrow indicates the magnitude and the direction of the arrow indicates the direction of the vector.
57. What is the result when two vectors are added together using the head-to-tail method?
ⓐ. The sum is a scalar quantity
ⓑ. The sum is another vector
ⓒ. The sum is always zero
ⓓ. The sum is a dot product
Explanation: When two vectors are added together using the head-to-tail method, the resultant is another vector that represents the combined effect of the original vectors.
58. Which of the following represents the magnitude of a vector?
ⓐ. The direction of the vector
ⓑ. The length of the vector arrow
ⓒ. The position of the vector arrow
ⓓ. The color of the vector arrow
Explanation: The magnitude of a vector is represented by the length of the arrow in vector diagrams, with longer arrows indicating larger magnitudes.
59. What is the term for a vector that has a magnitude of one?
ⓐ. Null vector
ⓑ. Unit vector
ⓒ. Scalar
ⓓ. Position vector
Explanation: A unit vector has a magnitude of one and is used to indicate direction without considering magnitude. It is often used to normalize other vectors.
60. Which operation is used to find the component of one vector along the direction of another vector?
ⓐ. Vector addition
ⓑ. Vector subtraction
ⓒ. Scalar multiplication
ⓓ. Dot product
Explanation: The dot product (or scalar product) of two vectors is used to find the component of one vector along the direction of another. It results in a scalar quantity and is calculated as the product of the magnitudes of the vectors and the cosine of the angle between them.
61. Which of the following is a scalar quantity?
ⓐ. Force
ⓑ. Velocity
ⓒ. Temperature
ⓓ. Displacement
Explanation: Temperature is a scalar quantity because it has only magnitude and no direction. It measures the degree of hotness or coldness of an object.
62. Which unit is used to measure mass?
ⓐ. Newton
ⓑ. Kilogram
ⓒ. Meter
ⓓ. Pascal
Explanation: The kilogram is the SI unit of mass. It measures the amount of matter in an object.
63. What does the magnitude of a scalar quantity represent?
ⓐ. The direction
ⓑ. The position
ⓒ. The size or amount
ⓓ. The angle
Explanation: The magnitude of a scalar quantity represents the size or amount of the quantity, such as the amount of mass or the degree of temperature.
64. Which of the following is not a scalar quantity?
ⓐ. Time
ⓑ. Speed
ⓒ. Acceleration
ⓓ. Energy
Explanation: Acceleration is a vector quantity because it has both magnitude and direction, indicating the rate of change of velocity.
65. How is temperature typically measured?
ⓐ. In meters
ⓑ. In kilograms
ⓒ. In degrees Celsius or Fahrenheit
ⓓ. In newtons
Explanation: Temperature is commonly measured in degrees Celsius (°C) or Fahrenheit (°F). The Kelvin (K) is the SI unit for temperature.
66. What is the primary characteristic of a scalar quantity?
ⓐ. It has both magnitude and direction
ⓑ. It has only direction
ⓒ. It has only magnitude
ⓓ. It has no physical meaning
Explanation: A scalar quantity is defined solely by its magnitude and does not include any information about direction.
67. Which of the following statements is true about mass?
ⓐ. It is a vector quantity
ⓑ. It is measured in joules
ⓒ. It is dependent on gravity
ⓓ. It remains constant regardless of location
Explanation: Mass is a scalar quantity that remains constant regardless of location. It is not dependent on gravity, unlike weight.
68. In what unit is temperature commonly expressed in scientific contexts?
ⓐ. Kelvin
ⓑ. Joule
ⓒ. Meter
ⓓ. Newton
Explanation: In scientific contexts, temperature is often expressed in Kelvin (K), which is the SI base unit for temperature and is used to measure absolute temperature.
69. Which of the following quantities does not change with direction?
ⓐ. Displacement
ⓑ. Velocity
ⓒ. Temperature
ⓓ. Force
Explanation: Temperature is a scalar quantity and does not change with direction. It only has magnitude, indicating how hot or cold something is.
70. Which statement best describes the mass of an object?
ⓐ. It changes when the object is moved to a different location
ⓑ. It is the amount of space the object occupies
ⓒ. It is the amount of matter in the object
ⓓ. It is the force exerted by the object
Explanation: The mass of an object is the amount of matter it contains. Unlike weight, which is a force that depends on gravity, mass is a scalar quantity and does not change with location.
71. Which of the following is a vector quantity?
ⓐ. Temperature
ⓑ. Mass
ⓒ. Displacement
ⓓ. Time
Explanation: Displacement is a vector quantity because it has both magnitude and direction. It represents the change in position of an object.
72. What distinguishes a vector quantity from a scalar quantity?
ⓐ. Vectors have only magnitude
ⓑ. Vectors have magnitude and direction
ⓒ. Scalars have magnitude and direction
ⓓ. Scalars have only direction
Explanation: Vector quantities have both magnitude and direction, unlike scalar quantities, which have only magnitude.
73. Which of the following is an example of a vector quantity?
ⓐ. Speed
ⓑ. Distance
ⓒ. Velocity
ⓓ. Energy
Explanation: Velocity is a vector quantity because it specifies both the speed of an object and the direction of its motion.
74. How is displacement different from distance?
ⓐ. Displacement is a scalar quantity; distance is a vector quantity
ⓑ. Displacement measures the total path length; distance measures the shortest path
ⓒ. Displacement is always greater than distance
ⓓ. Displacement measures the shortest path between two points, including direction; distance measures the total path length traveled
Explanation: Displacement is a vector quantity that represents the shortest path between two points and includes direction, while distance is a scalar quantity that measures the total path length traveled, regardless of direction.
75. What is the SI unit of velocity?
ⓐ. Meter per second (m/s)
ⓑ. Kilometer per hour (km/h)
ⓒ. Meter (m)
ⓓ. Second (s)
Explanation: The SI unit of velocity is meter per second (m/s). Velocity includes both the speed of an object and its direction of motion.
76. Which of the following best describes velocity?
ⓐ. The total distance traveled by an object
ⓑ. The speed of an object in a specific direction
ⓒ. The rate of change of distance
ⓓ. The scalar measure of how fast something is moving
Explanation: Velocity is defined as the speed of an object in a specific direction, making it a vector quantity.
77. How can two vectors be added?
ⓐ. By multiplying their magnitudes
ⓑ. By adding their magnitudes
ⓒ. By using the head-to-tail method or parallelogram method
ⓓ. By subtracting their magnitudes
Explanation: Two vectors can be added using the head-to-tail method or the parallelogram method, both of which take into account their magnitudes and directions.
78. Which of the following operations cannot be performed directly on vector quantities?
ⓐ. Addition
ⓑ. Subtraction
ⓒ. Multiplication by a scalar
ⓓ. Division by a vector
Explanation: Division by a vector is not a standard operation in vector mathematics. Vectors can be added, subtracted, and multiplied by scalars, but division by a vector is not defined.
79. What is the result of multiplying a vector by a scalar?
ⓐ. A scalar quantity
ⓑ. A vector quantity
ⓒ. A vector with unchanged direction but scaled magnitude
ⓓ. A vector with unchanged magnitude but scaled direction
Explanation: When a vector is multiplied by a scalar, the resulting vector has the same direction as the original vector but its magnitude is scaled by the scalar.
80. Which of the following quantities is a measure of how fast an object is moving in a specific direction?
ⓐ. Speed
ⓑ. Velocity
ⓒ. Distance
ⓓ. Mass
Explanation: Velocity measures how fast an object is moving in a specific direction. Unlike speed, which is a scalar quantity, velocity is a vector quantity that includes direction.
81. How is the magnitude of a vector typically represented in a diagram?
ⓐ. By the color of the arrow
ⓑ. By the length of the arrow
ⓒ. By the width of the arrow
ⓓ. By the angle of the arrow
Explanation: The magnitude of a vector is represented by the length of the arrow in a diagram. Longer arrows indicate larger magnitudes.
82. Which of the following best describes the direction of a vector?
ⓐ. The mass of the vector
ⓑ. The speed of the vector
ⓒ. The orientation of the arrow
ⓓ. The position of the arrow’s tail
Explanation: The direction of a vector is indicated by the orientation of the arrow in the vector diagram.
83. What information does a vector arrow convey in a vector diagram?
ⓐ. Only the direction
ⓑ. Only the magnitude
ⓒ. Both magnitude and direction
ⓓ. Only the origin
Explanation: A vector arrow in a vector diagram conveys both the magnitude (length of the arrow) and the direction (orientation of the arrow).
84. How can the direction of a vector be specified in a two-dimensional plane?
ⓐ. By its color
ⓑ. By its coordinates or an angle with a reference axis
ⓒ. By its weight
ⓓ. By its temperature
Explanation: In a two-dimensional plane, the direction of a vector can be specified by its coordinates (x, y) or by the angle it makes with a reference axis, usually the x-axis.
85. What is a unit vector?
ⓐ. A vector with zero magnitude
ⓑ. A vector with a magnitude of one
ⓒ. A vector with no direction
ⓓ. A vector with infinite magnitude
Explanation: A unit vector is a vector with a magnitude of one. It is used to indicate direction without considering magnitude.
86. How is a unit vector typically denoted?
ⓐ. With a double underline
ⓑ. With a hat or caret symbol (^)
ⓒ. With a prime symbol (‘)
ⓓ. With a tilde (~)
Explanation: A unit vector is typically denoted with a hat or caret symbol (^) above the variable, such as \(\hat{i}\), \(\hat{j}\), or \(\hat{k}\).
87. If vector \(\mathbf{A}\) has components \(A_x = 3\) and \(A_y = 4\), what is its magnitude?
ⓐ. 5
ⓑ. 7
ⓒ. 1
ⓓ. 12
Explanation: The magnitude of vector \(\mathbf{A}\) is found using the Pythagorean theorem: \(\sqrt{A_x^2 + A_y^2} = \sqrt{3^2 + 4^2} = \sqrt{9 + 16} = \sqrt{25} = 5\).
88. What does the angle of a vector represent in a vector diagram?
ⓐ. The color of the vector
ⓑ. The magnitude of the vector
ⓒ. The direction of the vector
ⓓ. The temperature of the vector
Explanation: The angle of a vector in a vector diagram represents the direction of the vector relative to a reference axis, typically the x-axis.
89. Which of the following correctly represents a vector with a magnitude of 10 units and an angle of 30 degrees from the positive x-axis?
ⓐ. \(10\hat{i}\)
ⓑ. \(10 \cos(30^\circ) \hat{i} + 10 \sin(30^\circ) \hat{j}\)
ⓒ. \(10 \hat{j}\)
ⓓ. \(10 \hat{i} + 30 \hat{j}\)
Explanation: A vector with a magnitude of 10 units and an angle of 30 degrees from the positive x-axis is represented as \(10 \cos(30^\circ) \hat{i} + 10 \sin(30^\circ) \hat{j}\).
90. How can vectors be represented algebraically in a three-dimensional space?
ⓐ. By using three scalar components
ⓑ. By using two scalar components
ⓒ. By using a single scalar component
ⓓ. By using no components
Explanation: In a three-dimensional space, vectors are represented algebraically by using three scalar components, typically denoted as \(x\), \(y\), and \(z\).
91. What are the horizontal and vertical components of a vector used for?
ⓐ. To determine the speed of an object
ⓑ. To find the mass of an object
ⓒ. To break down the vector into perpendicular directions
ⓓ. To measure the temperature and pressure
Explanation: The horizontal and vertical components of a vector are used to break down the vector into perpendicular directions, usually along the x and y axes in a coordinate system.
92. If a vector \(\mathbf{A}\) makes an angle \(\theta\) with the horizontal axis, what is the horizontal component of \(\mathbf{A}\)?
ⓐ. \(A \sin(\theta)\)
ⓑ. \(A \cos(\theta)\)
ⓒ. \(A \tan(\theta)\)
ⓓ. \(A \cot(\theta)\)
Explanation: The horizontal component of a vector \(\mathbf{A}\) is given by \(A \cos(\theta)\), where \(A\) is the magnitude of the vector and \(\theta\) is the angle with the horizontal axis.
93. If a vector \(\mathbf{A}\) makes an angle \(\theta\) with the horizontal axis, what is the vertical component of \(\mathbf{A}\)?
ⓐ. \(A \sin(\theta)\)
ⓑ. \(A \cos(\theta)\)
ⓒ. \(A \tan(\theta)\)
ⓓ. \(A \cot(\theta)\)
Explanation: The vertical component of a vector \(\mathbf{A}\) is given by \(A \sin(\theta)\), where \(A\) is the magnitude of the vector and \(\theta\) is the angle with the horizontal axis.
94. What are the horizontal and vertical components of a vector \(\mathbf{A}\) with magnitude 5 units and angle 60 degrees with the horizontal?
ⓐ. 2.5 units and 2.5 units
ⓑ. 5 units and 5 units
ⓒ. \(2.5\sqrt{3}\) units and 2.5 units
ⓓ. \(2.5\sqrt{3}\) units and \(2.5\sqrt{3}\) units
Explanation: For a vector with magnitude 5 units and angle 60 degrees, the horizontal component is \(5 \cos(60^\circ) = 5 \times \frac{1}{2} = 2.5\) units and the vertical component is \(5 \sin(60^\circ) = 5 \times \frac{\sqrt{3}}{2} = 2.5\sqrt{3}\) units.
95. If the horizontal component of a vector is 3 units and the vertical component is 4 units, what is the magnitude of the vector?
ⓐ. 5 units
ⓑ. 7 units
ⓒ. 1 unit
ⓓ. 12 units
Explanation: The magnitude of the vector is found using the Pythagorean theorem: \(\sqrt{3^2 + 4^2} = \sqrt{9 + 16} = \sqrt{25} = 5\) units.
96. What is the angle \(\theta\) with the horizontal axis for a vector with horizontal component 3 units and vertical component 4 units?
ⓐ. \( \tan^{-1}(\frac{4}{3}) \)
ⓑ. \( \sin^{-1}(\frac{4}{3}) \)
ⓒ. \( \cos^{-1}(\frac{4}{3}) \)
ⓓ. \( \tan^{-1}(\frac{3}{4}) \)
Explanation: The angle \(\theta\) is given by \( \tan(\theta) = \frac{4}{3} \). Therefore, \(\theta = \tan^{-1}(\frac{4}{3})\).
97. A vector \(\mathbf{B}\) has a horizontal component of 6 units and makes an angle of 30 degrees with the horizontal. What is the magnitude of \(\mathbf{B}\)?
ⓐ. 6 units
ⓑ. \(6\sqrt{3}\) units
ⓒ. 12 units
ⓓ. \(12\sqrt{3}\) units
Explanation: The horizontal component is given by \(B \cos(30^\circ)\). Therefore, \(B = \frac{6}{\cos(30^\circ)} = \frac{6}{\frac{\sqrt{3}}{2}} = 6 \times \frac{2}{\sqrt{3}} = 12\) units.
98. A vector \(\mathbf{C}\) has a vertical component of 8 units and makes an angle of 45 degrees with the horizontal. What is the magnitude of \(\mathbf{C}\)?
ⓐ. 8 units
ⓑ. \(8\sqrt{2}\) units
ⓒ. 16 units
ⓓ. \(16\sqrt{2}\) units
Explanation: The vertical component is given by \(C \sin(45^\circ)\). Therefore, \(C = \frac{8}{\sin(45^\circ)} = \frac{8}{\frac{\sqrt{2}}{2}} = 8 \times \frac{2}{\sqrt{2}} = 8\sqrt{2}\) units.
99. How do you find the resultant vector from its horizontal and vertical components?
ⓐ. By adding the components
ⓑ. By subtracting the components
ⓒ. By using the Pythagorean theorem
ⓓ. By dividing the components
Explanation: The resultant vector can be found using the Pythagorean theorem, where the magnitude of the resultant vector is the square root of the sum of the squares of the horizontal and vertical components.
100. What are the horizontal and vertical components of a vector \(\mathbf{D}\) with magnitude 10 units and angle 45 degrees with the horizontal?
ⓐ. 5 units and 5 units
ⓑ. \(10\sqrt{2}\) units and \(10\sqrt{2}\) units
ⓒ. \(5\sqrt{2}\) units and \(5\sqrt{2}\) units
ⓓ. \(10/\sqrt{2}\) units and \(10/\sqrt{2}\) units
Explanation: For a vector with magnitude 10 units and angle 45 degrees, the horizontal and vertical components are \(10 \cos(45^\circ) = 10 \times \frac{1}{\sqrt{2}} = \frac{10}{\sqrt{2}}\) units and \(10 \sin(45^\circ) = 10 \times \frac{1}{\sqrt{2}} = \frac{10}{\sqrt{2}}\) units.
101. What happens to the magnitude of a vector when it undergoes scalar multiplication?
ⓐ. It decreases
ⓑ. It increases
ⓒ. It remains the same
ⓓ. It becomes negative
Explanation: Scalar multiplication of a vector by a scalar quantity increases the magnitude of the vector proportionally.
102. If vector \(\mathbf{A}\) has a magnitude of 5 units, what is the magnitude of \(2\mathbf{A}\)?
ⓐ. 5 units
ⓑ. 10 units
ⓒ. 15 units
ⓓ. 25 units
Explanation: Scalar multiplication \(2\mathbf{A}\) multiplies the magnitude of vector \(\mathbf{A}\) by 2. Therefore, if \(\mathbf{A}\) has a magnitude of 5 units, \(2\mathbf{A}\) will have a magnitude of \(2 \times 5 = 10\) units.
103. If vector \(\mathbf{B}\) has a magnitude of 10 units, what is the magnitude of \(-\frac{1}{2}\mathbf{B}\)?
ⓐ. 5 units
ⓑ. 10 units
ⓒ. 15 units
ⓓ. 20 units
Explanation: Scalar multiplication \(-\frac{1}{2}\mathbf{B}\) multiplies the magnitude of vector \(\mathbf{B}\) by \(\frac{1}{2}\). Therefore, if \(\mathbf{B}\) has a magnitude of 10 units, \(-\frac{1}{2}\mathbf{B}\) will have a magnitude of \(\frac{1}{2} \times 10 = 5\) units.
104. What happens to the direction of a vector when it undergoes scalar multiplication?
ⓐ. It remains unchanged
ⓑ. It reverses
ⓒ. It becomes orthogonal
ⓓ. It rotates
Explanation: Scalar multiplication affects the magnitude of a vector but does not change its direction. The direction remains the same.
105. If vector \(\mathbf{C}\) has components \(C_x = 3\) and \(C_y = 4\), what are the components of \(2\mathbf{C}\)?
ⓐ. \(2C_x = 6\) and \(2C_y = 8\)
ⓑ. \(2C_x = 3\) and \(2C_y = 4\)
ⓒ. \(2C_x = 6\) and \(2C_y = 4\)
ⓓ. \(2C_x = 3\) and \(2C_y = 8\)
Explanation: Scalar multiplication \(2\mathbf{C}\) multiplies each component of vector \(\mathbf{C}\) by 2. Therefore, if \(C_x = 3\) and \(C_y = 4\), then \(2\mathbf{C}\) will have components \(2C_x = 6\) and \(2C_y = 8\).
106. If vector \(\mathbf{D}\) has components \(D_x = -2\) and \(D_y = 5\), what are the components of \(-\frac{1}{2}\mathbf{D}\)?
ⓐ. \(-\frac{1}{2}D_x = -1\) and \(-\frac{1}{2}D_y = -2.5\)
ⓑ. \(-\frac{1}{2}D_x = 1\) and \(-\frac{1}{2}D_y = 2.5\)
ⓒ. \(-\frac{1}{2}D_x = -1\) and \(-\frac{1}{2}D_y = 2.5\)
ⓓ. \(-\frac{1}{2}D_x = 1\) and \(-\frac{1}{2}D_y = -2.5\)
Explanation: Scalar multiplication \(-\frac{1}{2}\mathbf{D}\) multiplies each component of vector \(\mathbf{D}\) by \(-\frac{1}{2}\). Therefore, if \(D_x = -2\) and \(D_y = 5\), then \(-\frac{1}{2}\mathbf{D}\) will have components \(-\frac{1}{2}D_x = -1\) and \(-\frac{1}{2}D_y = 2.5\).
107. If \(\mathbf{E}\) is a vector with components \(E_x = 4\) and \(E_y = 3\), what are the components of \(3\mathbf{E}\)?
ⓐ. \(3E_x = 12\) and \(3E_y = 9\)
ⓑ. \(3E_x = 4\) and \(3E_y = 3\)
ⓒ. \(3E_x = 12\) and \(3E_y = 3\)
ⓓ. \(3E_x = 4\) and \(3E_y = 9\)
Explanation: Scalar multiplication \(3\mathbf{E}\) multiplies each component of vector \(\mathbf{E}\) by 3. Therefore, if \(E_x = 4\) and \(E_y = 3\), then \(3\mathbf{E}\) will have components \(3E_x = 12\) and \(3E_y = 9\).
108. If vector \(\mathbf{F}\) has a magnitude of 8 units, what is the magnitude of \(\frac{1}{4}\mathbf{F}\)?
ⓐ. 1 units
ⓑ. 2 units
ⓒ. 6 units
ⓓ. 8 units
Explanation: Scalar multiplication \(\frac{1}{4}\mathbf{F}\) multiplies the magnitude of vector \(\mathbf{F}\) by \(\frac{1}{4}\). Therefore, if \(\mathbf{F}\) has a magnitude of 8 units, \(\frac{1}{4}\mathbf{F}\) will have a magnitude of \(\frac{1}{4} \times 8 = 2\) units.
109. If vector \(\mathbf{G}\) has a horizontal component \(G_x = 6\) and vertical component \(G_y = 8\), what are the components of \(5\mathbf{G}\)?
ⓐ. \(5G_x = 30\) and \(5G_y = 40\)
ⓑ. \(5G_x = 6\) and \(5G_y = 8\)
ⓒ. \(5G_x = 30\) and \(5G_y = 8\)
ⓓ. \(5G_x = 6\) and \(5G_y = 40\)
Explanation: Scalar multiplication \(5\mathbf{G}\) multiplies each component of vector \(\mathbf{G}\) by 5. Therefore, if \(G_x = 6\) and \(G_y = 8\), then \(5\mathbf{G}\) will have components \(5G_x = 30\) and \(5G_y = 40\).
110. What is the result of multiplying a vector by zero?
ⓐ. The vector’s magnitude becomes zero
ⓑ. The vector’s direction changes
ⓒ. The vector remains unchanged
ⓓ. The vector becomes undefined
Explanation: Scalar multiplication of a vector by zero results in a vector with zero magnitude, regardless of its original direction.
111. When adding two vectors graphically, the resultant vector is represented by:
ⓐ. The difference between the two vectors
ⓑ. The sum of the two vectors
ⓒ. The average of the two vectors
ⓓ. The product of the two vectors
Explanation: Graphically, when adding two vectors, the resultant vector is represented by the vector sum of the two original vectors.
112. In a graphical vector addition, the tail of the second vector is placed:
ⓐ. At the head of the first vector
ⓑ. At the tail of the first vector
ⓒ. Opposite to the direction of the first vector
ⓓ. At a random point on the plane
Explanation: To add vectors graphically, the tail of the second vector is placed at the head of the first vector.
113. Vectors \(\mathbf{A}\) and \(\mathbf{B}\) are represented graphically by arrows with lengths 5 cm and 3 cm, respectively, and pointing in the same direction. What is the magnitude of their resultant vector?
ⓐ. 8 cm
ⓑ. 2 cm
ⓒ. 15 cm
ⓓ. 1 cm
Explanation: When vectors are added graphically in the same direction, their lengths are added to find the magnitude of the resultant vector. Therefore, \(|\mathbf{A} + \mathbf{B}| = 5 \text{ cm} + 3 \text{ cm} = 8 \text{ cm}\).
114. Vectors \(\mathbf{C}\) and \(\mathbf{D}\) are represented graphically by arrows with lengths 4 cm and 6 cm, respectively, and pointing in opposite directions. What is the magnitude of their resultant vector?
ⓐ. 10 cm
ⓑ. 2 cm
ⓒ. 15 cm
ⓓ. 2 cm
Explanation: When vectors are added graphically in opposite directions, their lengths are subtracted to find the magnitude of the resultant vector. Therefore, \(|\mathbf{C} + \mathbf{D}| = |4 \text{ cm} – 6 \text{ cm}| = 2 \text{ cm}\).
115. Vectors \(\mathbf{E}\) and \(\mathbf{F}\) are represented graphically by arrows with lengths 7 cm and 3 cm, respectively, and are perpendicular to each other. What is the magnitude of their resultant vector?
ⓐ. 8 cm
ⓑ. 7.5 cm
ⓒ. 7 cm
ⓓ. 7.62 cm
Explanation: When vectors are added graphically at right angles (perpendicular vectors), the magnitude of the resultant vector is found using the Pythagorean theorem. Therefore, \(|\mathbf{E} + \mathbf{F}| = \sqrt{7^2 + 3^2} = \sqrt{49 + 9} = \sqrt{58} \approx 7.62 \text{ cm}\).
116. Vectors \(\mathbf{G}\) and \(\mathbf{H}\) are represented graphically by arrows with lengths 6 cm and 8 cm, respectively, and are in opposite directions. What is the magnitude of their resultant vector?
ⓐ. 2 cm
ⓑ. 14 cm
ⓒ. 3 cm
ⓓ. 10 cm
Explanation: When vectors are added graphically in opposite directions, their lengths are added to find the magnitude of the resultant vector. Therefore, \(|\mathbf{G} + \mathbf{H}| = |6 \text{ cm} + 8 \text{ cm}| = 14 \text{ cm}\).
117. Vectors \(\mathbf{I}\) and \(\mathbf{J}\) are represented graphically by arrows with lengths 10 cm and 5 cm, respectively, and are in the same direction. What is the magnitude of their resultant vector?
ⓐ. 15 cm
ⓑ. 5 cm
ⓒ. 3 cm
ⓓ. 10 cm
Explanation: When vectors are added graphically in the same direction, their lengths are added to find the magnitude of the resultant vector. Therefore, \(|\mathbf{I} + \mathbf{J}| = 10 \text{ cm} + 5 \text{ cm} = 15 \text{ cm}\).
118. Vectors \(\mathbf{K}\) and \(\mathbf{L}\) are represented graphically by arrows with lengths 12 cm and 9 cm, respectively, and are at an angle of 60 degrees to each other. What is the magnitude of their resultant vector?
ⓐ. 11.13 cm
ⓑ. 12.16 cm
ⓒ. 15.76 cm
ⓓ. 18.26 cm
Explanation: When vectors are added graphically at an angle, the magnitude of the resultant vector can be found using the cosine rule or by resolving the vectors into components. Given that they are at an angle of 60 degrees, the magnitude of the resultant vector is \(|\mathbf{K} + \mathbf{L}| = \sqrt{12^2 + 9^2 + 2 \times 12 \times 9 \times \cos(60^\circ)} = \sqrt{144 + 81 + 108} = \sqrt{333} \approx 18.26 \text{ cm}\).
119. Vectors \(\mathbf{M}\) and \(\mathbf{N}\) are represented graphically by arrows with lengths 8 cm and 6 cm, respectively, and are at an angle of 120 degrees to each other. What is the magnitude of their resultant vector?
ⓐ. 6.21 cm
ⓑ. 7.21 cm
ⓒ. 8.21 cm
ⓓ. 9.21 cm
Explanation: When vectors are added graphically at an angle, the magnitude of the resultant vector can be found using the cosine rule or by resolving the vectors into components. Given that they are at an angle of 120 degrees, the magnitude of the resultant vector is \(|\mathbf{M} + \mathbf{N}| = \sqrt{8^2 + 6^2 + 2 \times 8 \times 6 \times \cos(120^\circ)} = \sqrt{64 + 36 – 48} = \sqrt{52} \approx 7.21 \text{ cm}\).
120. Vectors \(\mathbf{P}\) and \(\mathbf{Q}\) are represented graphically by arrows with lengths 10 cm and 5 cm, respectively, and are at an angle of 90 degrees to each other. What is the magnitude of their resultant vector?
ⓐ. 11.81 cm
ⓑ. 81.11 cm
ⓒ. 18.11 cm
ⓓ. 11.18 cm
Explanation: When vectors are added graphically at right angles (perpendicular vectors), the magnitude of the resultant vector is found using the Pythagorean theorem. Therefore, \(|\mathbf{P} + \mathbf{Q}| = \sqrt{10^2 + 5^2} = \sqrt{100 + 25} = \sqrt{125} \approx 11.18 \text{ cm}\).
121. According to the Triangle Law of Vector Addition, the resultant of two vectors can be found by:
ⓐ. Multiplying the two vectors
ⓑ. Dividing the two vectors
ⓒ. Adding the two vectors
ⓓ. Subtracting the two vectors
Explanation: The Triangle Law of Vector Addition states that to find the resultant of two vectors, you add them together vectorially.
122. Vectors \(\mathbf{A}\) and \(\mathbf{B}\) are represented by arrows with lengths 5 units and 3 units, respectively, and they act along the same straight line. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 2 units
ⓑ. 8 units
ⓒ. 15 units
ⓓ. 1 unit
Explanation: When vectors act along the same straight line, their resultant using the Triangle Law of Vector Addition is simply the sum of their magnitudes. Therefore, \(|\mathbf{A} + \mathbf{B}| = 5 \text{ units} + 3 \text{ units} = 8 \text{ units}\).
123. Vectors \(\mathbf{C}\) and \(\mathbf{D}\) are represented by arrows with lengths 4 units and 6 units, respectively, and they act in opposite directions along the same straight line. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 10 units
ⓑ. 2 units
ⓒ. 15 units
ⓓ. 2 units
Explanation: When vectors act in opposite directions along the same straight line, their resultant using the Triangle Law of Vector Addition is the absolute difference of their magnitudes. Therefore, \(|\mathbf{C} + \mathbf{D}| = |4 \text{ units} – 6 \text{ units}| = 2 \text{ units}\).
124. Vectors \(\mathbf{E}\) and \(\mathbf{F}\) are represented by arrows with lengths 7 units and 3 units, respectively, and they act at right angles to each other. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 6.62 units
ⓑ. 7.62 units
ⓒ. 8.62 units
ⓓ. 9.62 units
Explanation: When vectors act at right angles to each other, the magnitude of their resultant using the Triangle Law of Vector Addition is found using the Pythagorean theorem. Therefore, \(|\mathbf{E} + \mathbf{F}| = \sqrt{7^2 + 3^2} = \sqrt{49 + 9} = \sqrt{58} \approx 7.62 \text{ units}\).
125. Vectors \(\mathbf{G}\) and \(\mathbf{H}\) are represented by arrows with lengths 6 units and 8 units, respectively, and they act in opposite directions along the same straight line. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 2 units
ⓑ. 14 units
ⓒ. 3 units
ⓓ. 10 units
Explanation: When vectors act in opposite directions along the same straight line, their resultant using the Triangle Law of Vector Addition is the absolute sum of their magnitudes. Therefore, \(|\mathbf{G} + \mathbf{H}| = |6 \text{ units} + 8 \text{ units}| = 14 \text{ units}\).
126. Vectors \(\mathbf{I}\) and \(\mathbf{J}\) are represented by arrows with lengths 10 units and 5 units, respectively, and they act at an angle of 120 degrees to each other. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 5.66 units
ⓑ. 6.66 units
ⓒ. 7.66 units
ⓓ. 8.66 units
Explanation: When vectors act at an angle to each other, the magnitude of their resultant using the Triangle Law of Vector Addition can be found using the cosine rule or by resolving the vectors into components. Given that they are at an angle of 120 degrees, \(|\mathbf{I} + \mathbf{J}| = \sqrt{10^2 + 5^2 + 2 \times 10 \times 5 \times \cos(120^\circ)} = \sqrt{100 + 25 – 50} = \sqrt{75} = 5\sqrt{3} \approx 8.66 \text{ units}\).
127. Vectors \(\mathbf{K}\) and \(\mathbf{L}\) are represented by arrows with lengths 12 units and 9 units, respectively, and they act at an angle of 60 degrees to each other. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 11.28 units
ⓑ. 16.18 units
ⓒ. 18.26 units
ⓓ. 26.18 units
Explanation: When vectors act at an angle to each other, the magnitude of their resultant using the Triangle Law of Vector Addition can be found using the cosine rule or by resolving the vectors into components. Given that they are at an angle of 60 degrees, \(|\mathbf{K} + \mathbf{L}| = \sqrt{12^2 + 9^2 + 2 \times 12 \times 9 \times \cos(60^\circ)} = \sqrt{144 + 81 + 108} = \sqrt{333} \approx 18.26 \text{ units}\).
128. Vectors \(\mathbf{M}\) and \(\mathbf{N}\) are represented by arrows with lengths 8 units and 6 units, respectively, and they act at an angle of 120 degrees to each other. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 7=6.21 units
ⓑ. 7.21 units
ⓒ. 8.21 units
ⓓ. 14 units
Explanation: When vectors act at an angle to each other, the magnitude of their resultant using the Triangle Law of Vector Addition can be found using the cosine rule or by resolving the vectors into components. Given that they are at an angle of 120 degrees, \(|\mathbf{M} + \mathbf{N}| = \sqrt{8^2 + 6^2 + 2 \times 8 \times 6 \times \cos(120^\circ)} = \sqrt{64 + 36 – 48} = \sqrt{52} \approx 7.21 \text{ units}\).
129. Vectors \(\mathbf{P}\) and \(\mathbf{Q}\) are represented by arrows with lengths 10 units and 5 units, respectively, and they act at an angle of 90 degrees to each other. What is the magnitude of their resultant vector using the Triangle Law of Vector Addition?
ⓐ. 11.18 units
ⓑ. 18.11 units
ⓒ. 3 units
ⓓ. 10.18 units
Explanation: When vectors act at right angles (perpendicular vectors), the magnitude of their resultant using the Triangle Law of Vector Addition can be found using the Pythagorean theorem. Therefore, \(|\mathbf{P} + \mathbf{Q}| = \sqrt{10^2 + 5^2} = \sqrt{100 + 25} = \sqrt{125} \approx 11.18 \text{ units}\).
130. A vector \(\mathbf{V}\) has a magnitude of 10 units and makes an angle of 30 degrees with the horizontal. What are the horizontal and vertical components of \(\mathbf{V}\)?
ⓐ. Horizontal component = 5 units, Vertical component = 5 units
ⓑ. Horizontal component = 5√3 units, Vertical component = 5 units
ⓒ. Horizontal component = 5 units, Vertical component = 5√3 units
ⓓ. Horizontal component = 5√3 units, Vertical component = 5√3 units
Explanation: The horizontal component of \(\mathbf{V}\) can be found using \( V_x = V \cos(\theta) \), where \( V = 10 \) units and \( \theta = 30^\circ \). Therefore, \( V_x = 10 \cos(30^\circ) = 10 \times \frac{\sqrt{3}}{2} = 5 \) units. The vertical component \( V_y = V \sin(\theta) \) gives \( V_y = 10 \sin(30^\circ) = 10 \times \frac{1}{2} = 5 \) units.
131. A force of 20 N is applied at an angle of 60 degrees to the horizontal. What are the horizontal and vertical components of the force?
ⓐ. Horizontal component = 10 N, Vertical component = 10√3 N
ⓑ. Horizontal component = 10 N, Vertical component = 10 N
ⓒ. Horizontal component = 10√3 N, Vertical component = 10 N
ⓓ. Horizontal component = 10 N, Vertical component = 10/√3 N
Explanation: The horizontal component of the force can be found using \( F_x = F \cos(\theta) \), where \( F = 20 \) N and \( \theta = 60^\circ \). Therefore, \( F_x = 20 \cos(60^\circ) = 20 \times \frac{1}{2} = 10 \) N. The vertical component \( F_y = F \sin(\theta) \) gives \( F_y = 20 \sin(60^\circ) = 20 \times \frac{\sqrt{3}}{2} = 10\sqrt{3} \) N.
132. A velocity vector \(\mathbf{V}\) has a horizontal component of 8 m/s and a vertical component of 6 m/s. What is the magnitude of \(\mathbf{V}\)?
ⓐ. 14 m/s
ⓑ. 10 m/s
ⓒ. 12 m/s
ⓓ. 15 m/s
Explanation: The magnitude of vector \(\mathbf{V}\) can be found using \( |\mathbf{V}| = \sqrt{V_x^2 + V_y^2} \), where \( V_x = 8 \) m/s and \( V_y = 6 \) m/s. Therefore, \( |\mathbf{V}| = \sqrt{8^2 + 6^2} = \sqrt{64 + 36} = \sqrt{100} = 10 \) m/s.
133. A displacement vector \(\mathbf{D}\) has a magnitude of 12 units. Its horizontal component is 9 units. What is the vertical component of \(\mathbf{D}\)?
ⓐ. 15 units
ⓑ. 8 units
ⓒ. 10 units
ⓓ. 3 units
Explanation: To find the vertical component \( D_y \) of vector \(\mathbf{D}\), use \( D_y = \sqrt{D^2 – D_x^2} \), where \( D = 12 \) units and \( D_x = 9 \) units. Therefore, \( D_y = \sqrt{12^2 – 9^2} = \sqrt{144 – 81} = \sqrt{63} \approx 8 \) units.
134. An object moves with a velocity of 10 m/s at an angle of 45 degrees to the horizontal. What are the horizontal and vertical components of its velocity?
ⓐ. Horizontal component = 5√2 m/s, Vertical component = 5√2 m/s
ⓑ. Horizontal component = 10 m/s, Vertical component = 10 m/s
ⓒ. Horizontal component = 5 m/s, Vertical component = 5 m/s
ⓓ. Horizontal component = 5√2 m/s, Vertical component = 5 m/s
Explanation: The horizontal component of velocity can be found using \( V_x = V \cos(\theta) \), where \( V = 10 \) m/s and \( \theta = 45^\circ \). Therefore, \( V_x = 10 \cos(45^\circ) = 10 \times \frac{\sqrt{2}}{2} = 5\sqrt{2} \) m/s. The vertical component \( V_y = V \sin(\theta) \) gives \( V_y = 10 \sin(45^\circ) = 10 \times \frac{\sqrt{2}}{2} = 5\sqrt{2} \) m/s.
135. A force vector \(\mathbf{F}\) has a horizontal component of 15 N and a vertical component of 20 N. What is the magnitude of \(\mathbf{F}\)?
ⓐ. 20 N
ⓑ. 25 N
ⓒ. 35 N
ⓓ. 18 N
Explanation: The magnitude of vector \(\mathbf{F}\) can be found using \( |\mathbf{F}| = \sqrt{F_x^2 + F_y^2} \), where \( F_x = 15 \) N and \( F_y = 20 \) N. Therefore, \( |\mathbf{F}| = \sqrt{15^2 + 20^2} = \sqrt{225 + 400} = \sqrt{625} = 25 \) N.
136. Given two vectors \(\mathbf{A} = 3\hat{i} – 4\hat{j}\) and \(\mathbf{B} = 2\hat{i} + 5\hat{j}\), what is the resultant vector \(\mathbf{A} + \mathbf{B}\)?
ⓐ. \(5\hat{i} + \hat{j}\)
ⓑ. \(5\hat{i} – \hat{j}\)
ⓒ. \(5\hat{i} + 9\hat{j}\)
ⓓ. \(5\hat{i} – 9\hat{j}\)
Explanation: To find the resultant vector \(\mathbf{A} + \mathbf{B}\), add the corresponding components: \( \mathbf{A} + \mathbf{B} = (3 + 2)\hat{i} + (-4 + 5)\hat{j} = 5\hat{i} + \hat{j} \).
137. If a vector \(\mathbf{V}\) has components \( V_x = 8 \) m and \( V_y = -6 \) m, what is the magnitude of \(\mathbf{V}\)?
ⓐ. 10 m
ⓑ. 5 m
ⓒ. 4 m
ⓓ. 12 m
Explanation: The magnitude of vector \(\mathbf{V}\) can be found using \( |\mathbf{V}| = \sqrt{V_x^2 + V_y^2} \), where \( V_x = 8 \) m and \( V_y = -6 \) m. Therefore, \( |\mathbf{V}| = \sqrt{8^2 + (-6)^2} = \sqrt{64 + 36} = \sqrt{100} = 10 \) m.
138. If vector \(\mathbf{A}\) has a magnitude of 5 units and makes an angle of 60 degrees with the positive x-axis, what are its components \(\mathbf{A}_x\) and \(\mathbf{A}_y\)?
ⓐ. \(\mathbf{A}_x = 2.5\) units, \(\mathbf{A}_y = 4.33\) units
ⓑ. \(\mathbf{A}_x = 4.33\) units, \(\mathbf{A}_y = 2.5\) units
ⓒ. \(\mathbf{A}_x = 5\) units, \(\mathbf{A}_y = 3\) units
ⓓ. \(\mathbf{A}_x = 3\) units, \(\mathbf{A}_y = 5\) units
Explanation: The x-component \(\mathbf{A}_x\) can be found using \( \mathbf{A}_x = A \cos(\theta) \) and the y-component \(\mathbf{A}_y\) using \( \mathbf{A}_y = A \sin(\theta) \), where \( A = 5 \) units and \( \theta = 60^\circ \). Therefore, \( \mathbf{A}_x = 5 \cos(60^\circ) = 5 \times \frac{1}{2} = 2.5 \) units and \( \mathbf{A}_y = 5 \sin(60^\circ) = 5 \times \frac{\sqrt{3}}{2} \approx 4.33 \) units.
139. If vector \(\mathbf{B}\) has components \(\mathbf{B}_x = 10\) m and \(\mathbf{B}_y = -8\) m, what is the angle \(\theta\) that \(\mathbf{B}\) makes with the positive x-axis?
ⓐ. 36.87 degrees
ⓑ. 53.13 degrees
ⓒ. 45 degrees
ⓓ. 60 degrees
Explanation: The angle \(\theta\) can be found using \( \theta = \tan^{-1}\left(\frac{\mathbf{B}_y}{\mathbf{B}_x}\right) \), where \( \mathbf{B}_x = 10 \) m and \( \mathbf{B}_y = -8 \) m. Therefore, \( \theta = \tan^{-1}\left(\frac{-8}{10}\right) = \tan^{-1}(-0.8) \approx -36.87^\circ \), but since angle is measured with the positive x-axis, so answer is positive 36.
140. Given two vectors \(\mathbf{A} = 4\hat{i} – 3\hat{j}\) and \(\mathbf{B} = 2\hat{i} + 5\hat{j}\), what is the resultant vector \(\mathbf{A} + \mathbf{B}\)?
ⓐ. \(6\hat{i} + 2\hat{j}\)
ⓑ. \(2\hat{i} + 2\hat{j}\)
ⓒ. \(6\hat{i} + 8\hat{j}\)
ⓓ. \(2\hat{i} + 8\hat{j}\)
Explanation: To find the resultant vector \(\mathbf{A} + \mathbf{B}\), add the corresponding components: \( \mathbf{A} + \mathbf{B} = (4 + 2)\hat{i} + (-3 + 5)\hat{j} = 6\hat{i} + 2\hat{j} \).
141. If two forces \(\mathbf{F}_1 = 10 \hat{i} – 5 \hat{j}\) N and \(\mathbf{F}_2 = -3 \hat{i} + 7 \hat{j}\) N act on an object simultaneously, what is the resultant force?
ⓐ. \(7 \hat{i} + 2 \hat{j}\) N
ⓑ. \(8 \hat{i} + 2 \hat{j}\) N
ⓒ. \(7 \hat{i} + 12 \hat{j}\) N
ⓓ. \(8 \hat{i} + 12 \hat{j}\) N
Explanation: To find the resultant force, add the corresponding components: \( \mathbf{F}_{\text{resultant}} = (10 – 3) \hat{i} + (-5 + 7) \hat{j} = 7 \hat{i} + 2 \hat{j} \).
142. If a vector \(\mathbf{A}\) has components \( A_x = 8 \) m and \( A_y = -6 \) m, and vector \(\mathbf{B}\) has components \( B_x = 5 \) m and \( B_y = 4 \) m, what is the resultant vector \(\mathbf{A} + \mathbf{B}\)?
ⓐ. \(13 \hat{i} – 2 \hat{j}\) m
ⓑ. \(3 \hat{i} – 2 \hat{j}\) m
ⓒ. \(13 \hat{i} + 2 \hat{j}\) m
ⓓ. \(3 \hat{i} + 2 \hat{j}\) m
Explanation: To find the resultant vector \(\mathbf{A} + \mathbf{B}\), add the corresponding components: \( \mathbf{A} + \mathbf{B} = (8 + 5) \hat{i} + (-6 + 4) \hat{j} = 13 \hat{i} – 2 \hat{j} \).
143. If two velocity vectors \(\mathbf{V}_1 = 5 \hat{i} + 3 \hat{j}\) m/s and \(\mathbf{V}_2 = -2 \hat{i} + 4 \hat{j}\) m/s are added together, what is the resultant velocity?
ⓐ. \(3 \hat{i} + 7 \hat{j}\) m/s
ⓑ. \(3 \hat{i} – 1 \hat{j}\) m/s
ⓒ. \(7 \hat{i} + 7 \hat{j}\) m/s
ⓓ. \(7 \hat{i} – 1 \hat{j}\) m/s
Explanation: To find the resultant velocity, add the corresponding components: \( \mathbf{V}_{\text{resultant}} = (5 – 2) \hat{i} + (3 + 4) \hat{j} = 3 \hat{i} – 1 \hat{j} \).
144. Given vectors \(\mathbf{A} = 3 \hat{i} + 2 \hat{j}\) and \(\mathbf{B} = -\hat{i} + 5 \hat{j}\), what is the magnitude of the resultant vector \(\mathbf{A} + \mathbf{B}\)?
ⓐ. \(\sqrt{29}\)
ⓑ. \(\sqrt{26}\)
ⓒ. \(\sqrt{22}\)
ⓓ. \(\sqrt{25}\)
Explanation: To find the magnitude of the resultant vector, first find the components \(\mathbf{A} + \mathbf{B}\): \( \mathbf{A} + \mathbf{B} = (3 – 1) \hat{i} + (2 + 5) \hat{j} = 2 \hat{i} + 7 \hat{j} \). Then, \( |\mathbf{A} + \mathbf{B}| = \sqrt{(2)^2 + (7)^2} = \sqrt{4 + 49} = \sqrt{53} \).
145. Given vectors \(\mathbf{A} = 5 \hat{i} + 3 \hat{j}\) and \(\mathbf{B} = -2 \hat{i} + 4 \hat{j}\), what is the resultant vector \(\mathbf{A} + \mathbf{B}\)?
ⓐ. \(3 \hat{i} + 7 \hat{j}\)
ⓑ. \(7 \hat{i} + 1 \hat{j}\)
ⓒ. \(3 \hat{i} + 1 \hat{j}\)
ⓓ. \(7 \hat{i} + 7 \hat{j}\)
Explanation: To find the resultant vector \(\mathbf{A} + \mathbf{B}\), add the corresponding components: \( \mathbf{A} + \mathbf{B} = (5 – 2) \hat{i} + (3 + 4) \hat{j} = 3 \hat{i} + 7 \hat{j} \).
146. If two displacement vectors \(\mathbf{D}_1 = 8 \hat{i} – 3 \hat{j}\) m and \(\mathbf{D}_2 = -4 \hat{i} + 6 \hat{j}\) m are added together, what is the resultant displacement?
ⓐ. \(4 \hat{i} + 3 \hat{j}\) m
ⓑ. \(4 \hat{i} – 9 \hat{j}\) m
ⓒ. \(12 \hat{i} + 3 \hat{j}\) m
ⓓ. \(12 \hat{i} – 9 \hat{j}\) m
Explanation: To find the resultant displacement, add the corresponding components: \( \mathbf{D}_{\text{resultant}} = (8 – 4) \hat{i} + (-3 + 6) \hat{j} = 4 \hat{i} + 3 \hat{j} \).
147. Given vectors \(\mathbf{P} = -3 \hat{i} + 5 \hat{j}\) and \(\mathbf{Q} = 7 \hat{i} – 2 \hat{j}\), what is the magnitude of the resultant vector \(\mathbf{P} + \mathbf{Q}\)?
ⓐ. \(\sqrt{85}\)
ⓑ. \(\sqrt{76}\)
ⓒ. \(\sqrt{65}\)
ⓓ. \(\sqrt{61}\)
Explanation: To find the magnitude of the resultant vector, first find the components \(\mathbf{P} + \mathbf{Q}\): \( \mathbf{P} + \mathbf{Q} = (-3 + 7) \hat{i} + (5 – 2) \hat{j} = 4 \hat{i} + 3 \hat{j} \). Then, \( |\mathbf{P} + \mathbf{Q}| = \sqrt{(4)^2 + (3)^2} = \sqrt{16 + 9} = \sqrt{25} = 5 \) units.
148. If vectors \(\mathbf{V}_1 = 6 \hat{i} – 2 \hat{j}\) m/s and \(\mathbf{V}_2 = -3 \hat{i} + 4 \hat{j}\) m/s are added together, what is the direction of the resultant velocity relative to the positive x-axis?
ⓐ. \( \tan^{-1}\left(\frac{2}{6}\right) \)
ⓑ. \( \tan^{-1}\left(\frac{-2}{6}\right) \)
ⓒ. \( \tan^{-1}\left(\frac{4}{3}\right) \)
ⓓ. \( \tan^{-1}\left(\frac{-4}{3}\right) \)
Explanation: To find the direction of the resultant velocity, use \( \theta = \tan^{-1}\left(\frac{V_{\text{resultant, } y}}{V_{\text{resultant, } x}}\right) \), where \( V_{\text{resultant, } x} = 6 – 3 = 3 \) m/s and \( V_{\text{resultant, } y} = -2 + 4 = 2 \) m/s. Therefore, \( \theta = \tan^{-1}\left(\frac{2}{3}\right) \).
149. If vector \(\mathbf{U}_1 = 10 \hat{i}\) and vector \(\mathbf{U}_2 = 5 \hat{j}\) are added together, what is the resultant vector \(\mathbf{U}_1 + \mathbf{U}_2\)?
ⓐ. \(10 \hat{i} + 5 \hat{j}\)
ⓑ. \(15 \hat{i} + 5 \hat{j}\)
ⓒ. \(10 \hat{i} + 15 \hat{j}\)
ⓓ. \(15 \hat{i} + 15 \hat{j}\)
Explanation: To find the resultant vector, add the corresponding components: \( \mathbf{U}_1 + \mathbf{U}_2 = 10 \hat{i} + 5 \hat{j} \).
150. In a displacement problem, if a car moves 10 km east and then 8 km north, what is the magnitude of its resultant displacement from the starting point?
ⓐ. \(18\) km
ⓑ. \(12\) km
ⓒ. \(14\) km
ⓓ. \(15\) km
Explanation: To find the resultant displacement, use the Pythagorean theorem: \( \text{Resultant displacement} = \sqrt{(10)^2 + (8)^2} = \sqrt{100 + 64} = \sqrt{164} \approx 12 \) km.
151. Two forces \(\mathbf{F}_1 = 10 \hat{i} – 5 \hat{j}\) N and \(\mathbf{F}_2 = -3 \hat{i} + 7 \hat{j}\) N act on an object. What is the magnitude of the resultant force?
ⓐ. \(10.2\) N
ⓑ. \(11.2\) N
ⓒ. \(12.2\) N
ⓓ. \(13.2\) N
Explanation: To find the magnitude of the resultant force, use \( |\mathbf{F}_{\text{resultant}}| = \sqrt{(10 – 3)^2 + (-5 + 7)^2} = \sqrt{7^2 + 2^2} = \sqrt{49 + 4} = \sqrt{53} \approx 11.2 \) N.
152. A boat travels at a speed of \(6\) m/s in a direction \(30^\circ\) north of east. What are the horizontal and vertical components of its velocity?
ⓐ. Horizontal: \(5.2\) m/s, Vertical: \(5\) m/s
ⓑ. Horizontal: \(5\) m/s, Vertical: \(3.5\) m/s
ⓒ. Horizontal: \(3\) m/s, Vertical: \(5.2\) m/s
ⓓ. Horizontal: \(3.5\) m/s, Vertical: \(3\) m/s
Explanation: Horizontal component: \(6 \cos 30^\circ = 6 \cdot \frac{\sqrt{3}}{2} \approx 5.2\) m/s, Vertical component: \(6 \sin 30^\circ = 6 \cdot \frac{1}{2} = 3\) m/s.
153. A football player kicks a ball with a velocity of \(20\) m/s at an angle \(45^\circ\) above the horizontal. What are the horizontal and vertical components of the ball’s initial velocity?
ⓐ. Horizontal: \(10 \sqrt{2}\) m/s, Vertical: \(10 \sqrt{2}\) m/s
ⓑ. Horizontal: \(20 \sqrt{2}\) m/s, Vertical: \(20 \sqrt{2}\) m/s
ⓒ. Horizontal: \(10\) m/s, Vertical: \(10\) m/s
ⓓ. Horizontal: \(20\) m/s, Vertical: \(20\) m/s
Explanation: Horizontal component: \(20 \cos 45^\circ = 20 \cdot \frac{\sqrt{2}}{2} = 10 \sqrt{2}\) m/s, Vertical component: \(20 \sin 45^\circ = 20 \cdot \frac{\sqrt{2}}{2} = 10 \sqrt{2}\) m/s.
154. A pilot flies a plane at a speed of \(250\) km/h in a direction \(60^\circ\) south of west. What are the horizontal and vertical components of the plane’s velocity?
ⓐ. Horizontal: \(125\) km/h, Vertical: \(-\sqrt{3} \cdot 125\) km/h
ⓑ. Horizontal: \(125\) km/h, Vertical: \(125\) km/h
ⓒ. Horizontal: \(-\sqrt{3} \cdot 125\) km/h, Vertical: \(125\) km/h
ⓓ. Horizontal: \(125\) km/h, Vertical: \(-125\) km/h
Explanation: Horizontal component: \(250 \cos 60^\circ = 250 \cdot \frac{1}{2} = 125\) km/h, Vertical component: \(250 \sin 60^\circ = 250 \cdot \frac{\sqrt{3}}{2} \approx 125 \sqrt{3}\) km/h (south direction, so negative sign).
155. A projectile is launched with an initial velocity of \(20\) m/s at an angle \(30^\circ\) above the horizontal. What is the time of flight of the projectile?
ⓐ. \(2\) s
ⓑ. \(3\) s
ⓒ. \(4\) s
ⓓ. \(5\) s
Explanation: Time of flight \(T = \frac{2V_0 \sin \theta}{g} = \frac{2 \cdot 20 \cdot \sin 30^\circ}{9.8} = \frac{40 \cdot 0.5}{9.8} = \frac{20}{9.8} \approx 2.04\) s. Rounded to nearest whole number, \(T \approx 4\) s.
156. A ball is thrown horizontally from a cliff with an initial speed of \(15\) m/s. How far does the ball travel horizontally before hitting the ground, assuming \(g = 10\) m/s²?
ⓐ. \(30\) m
ⓑ. \(45\) m
ⓒ. \(60\) m
ⓓ. \(75\) m
Explanation: Horizontal range \(R = V_0 \cdot T = 15 \cdot \frac{2h}{g} = 15 \cdot \frac{2 \cdot 15}{10} = 30\) m.
157. A car travels along a circular track with a radius of \(50\) m at a constant speed of \(10\) m/s. What is the magnitude of its centripetal acceleration?
ⓐ. \(1\) m/s²
ⓑ. \(2\) m/s²
ⓒ. \(3\) m/s²
ⓓ. \(4\) m/s²
Explanation: Centripetal acceleration \(a_c = \frac{v^2}{r} = \frac{10^2}{50} = \frac{100}{50} = 2\) m/s².
158. A stone tied to a string is whirled in a horizontal circle with a constant speed of \(5\) m/s. If the string is \(4\) m long, what is the magnitude of the centripetal acceleration of the stone?
ⓐ. \(3.125\) m/s²
ⓑ. \(6.25\) m/s²
ⓒ. \(9.375\) m/s²
ⓓ. \(12.5\) m/s²
Explanation: Centripetal acceleration \(a_c = \frac{v^2}{r} = \frac{5^2}{4} = \frac{25}{4} = 6.25\) m/s².
159. An astronaut orbits the Earth in the International Space Station at an altitude where \(g \approx 8\) m/s². If the astronaut experiences a centripetal acceleration of \(10\) m/s², what is the radius of the astronaut’s orbit?
ⓐ. \(5\) m
ⓑ. \(6\) m
ⓒ. \(7\) m
ⓓ. \(8\) m
Explanation: Centripetal acceleration \(a_c = \frac{v^2}{r} = \frac{v^2}{g} = \frac{10}{8} = 1.25\). Radius \(r = \frac{v^2}{a_c} = \frac{10}{1.25} = 8\) m
160. What is the primary characteristic of uniform circular motion?
ⓐ. Constant speed and changing velocity
ⓑ. Changing speed and constant velocity
ⓒ. Constant speed and constant velocity
ⓓ. Changing speed and changing velocity
Explanation: In uniform circular motion, an object moves in a circle with a constant speed \(v\) and its velocity changes due to the direction of motion, always tangential to the circle.
161. A particle moves along the circumference of a circle with a constant speed of \(10\) m/s. What is the acceleration of the particle?
ⓐ. Zero
ⓑ. \(10\) m/s²
ⓒ. \(20\) m/s²
ⓓ. \(50\) m/s²
Explanation: The acceleration \(a\) in uniform circular motion is given by \( a = \frac{v^2}{r} \), where \(v\) is the speed of the particle and \(r\) is the radius of the circle.
162. In uniform circular motion, what provides the centripetal force necessary for the motion?
ⓐ. Gravity
ⓑ. Friction
ⓒ. Tension in the string
ⓓ. Normal force
Explanation: The centripetal force required for uniform circular motion can be provided by various forces like tension, friction, or gravity, depending on the specific scenario.
163. A car moves along a circular track with a radius of \(50\) meters at a constant speed. What happens to the car’s velocity as it moves along the track?
ⓐ. Constant speed, changing velocity
ⓑ. Changing speed, constant velocity
ⓒ. Constant speed, constant velocity
ⓓ. Changing speed, changing velocity
Explanation: In uniform circular motion, the speed of the car remains constant, but its velocity changes continuously due to the change in direction.
164. What is the role of centripetal force in uniform circular motion?
ⓐ. It increases the speed of the object.
ⓑ. It maintains the object’s constant speed.
ⓒ. It decreases the radius of the circular path.
ⓓ. It changes the object’s direction of motion.
Explanation: Centripetal force acts towards the center of the circular path and is responsible for keeping the object moving in a circle at a constant speed.
165. What is the formula for centripetal acceleration \(a_c\) of an object moving in a circle of radius \(r\) with speed \(v\)?
ⓐ. \(a_c = \frac{v}{r}\)
ⓑ. \(a_c = \frac{r}{v}\)
ⓒ. \(a_c = \frac{v^2}{r}\)
ⓓ. \(a_c = \frac{r^2}{v}\)
Explanation: Centripetal acceleration \(a_c = \frac{v^2}{r}\) points towards the center of the circle and depends on the square of the speed divided by the radius of the circle.
166. An object moves in a circle of radius \(10\) m with a speed of \(5\) m/s. What is its centripetal acceleration?
ⓐ. \(2\) m/s²
ⓑ. \(2.5\) m/s²
ⓒ. \(5.5\) m/s²
ⓓ. \(7.21\) m/s²
Explanation: Centripetal acceleration \(a_c = \frac{v^2}{r} = \frac{5^2}{10} = \frac{25}{10} = 2.5\) m/s².
167. What provides the centripetal force necessary to keep an object in uniform circular motion?
ⓐ. Gravity
ⓑ. Friction
ⓒ. Tension
ⓓ. Normal force
Explanation: Centripetal force required for uniform circular motion can be provided by various forces like tension, friction, or gravity, depending on the specific scenario.
168. A car moves around a circular track of radius \(100\) m with a speed of \(20\) m/s. What is the magnitude of the centripetal force acting on the car?
ⓐ. \(20\) N
ⓑ. \(200\) N
ⓒ. \(400\) N
ⓓ. \(4000\) N
Explanation: Centripetal force \(F_c = m \cdot \frac{v^2}{r} = m \cdot \frac{20^2}{100} = m \cdot 4\) N, where \(m\) is the mass of the car.
169. What happens to the centripetal force if the speed of an object in circular motion is doubled?
ⓐ. It remains the same.
ⓑ. It becomes half.
ⓒ. It quadruples.
ⓓ. It doubles.
Explanation: Centripetal force \(F_c = m \cdot \frac{v^2}{r}\). If \(v\) is doubled, \(v^2\) becomes four times larger, hence the centripetal force quadruples.
170. What is the definition of period \(T\) in the context of circular motion?
ⓐ. The time taken for one complete revolution
ⓑ. The distance traveled in one complete revolution
ⓒ. The speed of the object in circular motion
ⓓ. The angular displacement of the object in circular motion
Explanation: Period \(T\) is the time taken for one complete cycle or revolution in circular motion.
171. A wheel completes \(50\) revolutions in \(10\) seconds. What is the period of the wheel’s motion?
ⓐ. \(0.2\) s
ⓑ. \(0.5\) s
ⓒ. \(2\) s
ⓓ. \(5\) s
Explanation: Period \(T = \frac{\text{Total time}}{\text{Number of revolutions}} = \frac{10}{50} = 0.2\) s per revolution.
172. What is the formula for frequency \(f\) in circular motion?
ⓐ. \(f = \frac{1}{T}\)
ⓑ. \(f = \frac{T}{2\pi}\)
ⓒ. \(f = \frac{2\pi}{T}\)
ⓓ. \(f = \frac{T}{2}\)
Explanation: Frequency \(f\) is the number of cycles or revolutions per unit time, where \(T\) is the period.
173. If the period of oscillation of a pendulum is \(2\) seconds, what is its frequency?
ⓐ. \(0.5\) Hz
ⓑ. \(1\) Hz
ⓒ. \(2\) Hz
ⓓ. \(4\) Hz
Explanation: Frequency \(f = \frac{1}{T} = \frac{1}{2} = 0.5\) Hz, where \(T\) is the period in seconds.
174. What is the relationship between angular velocity \(\omega\), angular displacement \(\theta\), and time \(t\) in circular motion?
ⓐ. \(\omega = \frac{\theta}{t}\)
ⓑ. \(\omega = \frac{t}{\theta}\)
ⓒ. \(\omega = \frac{\theta}{2\pi}\)
ⓓ. \(\omega = \frac{2\pi}{\theta}\)
Explanation: Angular velocity \(\omega = \frac{\theta}{t}\) represents the rate of change of angular displacement with respect to time.
175. An object moves in a circle with a radius of \(2\) m. If it completes \(10\) revolutions in \(5\) seconds, what is its angular velocity?
ⓐ. \(1\) rad/s
ⓑ. \(2\) rad/s
ⓒ. \(5\) rad/s
ⓓ. \(10\) rad/s
Explanation: not available
176. An object moves in a circle with a radius of \(2\) m. If it completes \(10\) revolutions in \(5\) seconds, what is its angular velocity?
ⓐ. \(1\) rad/s
ⓑ. \(4\) rad/s
ⓒ. \(8\) rad/s
ⓓ. \(16\) rad/s
Explanation: Angular velocity \(\omega\) is calculated using the formula \(\omega = \frac{2\pi n}{T}\), where \(n\) is the number of revolutions and \(T\) is the time taken. Here, \(\omega = \frac{2\pi \cdot 10}{5} = 4\) rad/s.
177. What is the SI unit of angular velocity \(\omega\)?
ⓐ. radians
ⓑ. radians per second
ⓒ. revolutions per second
ⓓ. degrees per second
Explanation: Angular velocity is measured in radians per second (rad/s) in the SI unit system.
178. If the angular velocity of a rotating object is \(\frac{\pi}{3}\) rad/s and the radius of the circle is \(4\) m, what is the linear speed \(v\) of a point on the edge of the circle?
ⓐ. \(\frac{4\pi}{3}\) m/s
ⓑ. \(\frac{8\pi}{3}\) m/s
ⓒ. \(4\pi\) m/s
ⓓ. \(8\pi\) m/s
Explanation: Linear speed \(v\) is given by \(v = \omega \cdot r = \frac{\pi}{3} \cdot 4 = 4\pi\) m/s, where \(r\) is the radius and \(\omega\) is the angular velocity.
179. If a wheel has an angular velocity of \(10\) rad/s and a radius of \(0.5\) m, what is its linear speed \(v\) at a point on its edge?
ⓐ. \(2\) m/s
ⓑ. \(5\) m/s
ⓒ. \(10\) m/s
ⓓ. \(20\) m/s
Explanation: Linear speed \(v = \omega \cdot r = 10 \cdot 0.5 = 5\) m/s. The linear speed is directly proportional to the radius and angular velocity of the rotating object.