Test: Circular Motion (Chapter 5)

Multiple Choice Questions

  1. 1. Angular displacement (Δθ) defines the change in ___ of a rotating object.

  2. 2. For very small values, angular displacement (Δθ) is treated as a ___ quantity.

  3. 3. The direction of angular displacement vector is given by the:

  4. 4. The SI unit for angular displacement is:

  5. 5. One revolution is equal to ___ radians.

  6. 6. One radian is approximately equal to ___ degrees.

  7. 7. Angular velocity (ω) is defined as the rate of change of:

  8. 8. The SI unit for angular velocity is:

  9. 9. Angular acceleration (α) is defined as the rate of change of:

  10. 10. The SI unit for angular acceleration is:

  11. 11. The relationship between arc length (S), radius (r), and angular displacement (θ in radians) is:

  12. 12. The relationship between tangential velocity (v), radius (r), and angular velocity (ω) is:

  13. 13. The relationship between tangential acceleration (at), radius (r), and angular acceleration (α) is:

  14. 14. For a rigid body rotating about a fixed axis, do all points have the same angular velocity?

  15. 15. For a rigid body rotating about a fixed axis, do all points have the same tangential speed?

  16. 16. Which equation of angular motion is analogous to vf = vi + at?

  17. 17. Which equation of angular motion is analogous to 2aS = vf² - vi²?

  18. 18. The force required to keep an object moving in a circular path is called:

  19. 19. If the string holding a whirling ball snaps, the ball flies off along the:

  20. 20. An object moving with uniform speed in a circle experiences acceleration because its ___ is constantly changing.

  21. 21. Centripetal acceleration (ac) is always directed:

  22. 22. The magnitude of centripetal acceleration (ac) is given by:

  23. 23. Centripetal acceleration (ac) can also be expressed in terms of angular velocity (ω) as:

  24. 24. The magnitude of centripetal force (Fc) is given by:

  25. 25. Centripetal force (Fc) can also be expressed in terms of angular velocity (ω) as:

  26. 26. For a ball swung in a vertical circle, at the highest point, the tension T in the string is related to weight w and centripetal force Fc by:

  27. 27. For a ball swung in a vertical circle, at the lowest point (point A in Fig 5.7), the tension T in the string is related to weight w and centripetal force Fc by:

  28. 28. Moment of inertia (I) plays the same role in rotational motion as ___ plays in linear motion.

  29. 29. The moment of inertia of a single particle of mass m at a distance r from the axis of rotation is:

  30. 30. The rotational analogue of Newton's second law (F=ma) is:

  31. 31. The moment of inertia of a rigid body depends on its mass and:

  32. 32. The formula for the moment of inertia of a rigid body composed of n particles is:

  33. 33. The moment of inertia of a thin rod of length L rotating about its center is:

  34. 34. The moment of inertia of a thin ring or hoop of radius r rotating about its center is:

  35. 35. The moment of inertia of a solid disc or cylinder of radius r rotating about its central axis is:

  36. 36. The moment of inertia of a solid sphere of radius r rotating about its diameter is:

  37. 37. Angular momentum (L) is the rotational analogue of:

  38. 38. The angular momentum L of a particle with linear momentum p at position r from the origin O is defined as:

  39. 39. The magnitude of angular momentum L is given by:

  40. 40. The SI unit for angular momentum is:

  41. 41. For a particle moving in a circle of radius r with speed v, the magnitude of angular momentum is:

  42. 42. For a rigid body rotating with angular velocity ω and moment of inertia I, the angular momentum L is:

  43. 43. The angular momentum associated with the motion of a body along a circular path is called:

  44. 44. The Law of Conservation of Angular Momentum states that if no external ___ acts on a system, the total angular momentum remains constant.

  45. 45. When a diver pulls their arms and legs into a tuck position, their moment of inertia ___ and their angular velocity ___.

  46. 46. Why does the Earth's axis of rotation remain relatively fixed in direction as it orbits the Sun?

  47. 47. The rotational kinetic energy (KErot) of a body with moment of inertia I rotating with angular velocity ω is:

  48. 48. The rotational kinetic energy of a solid disc (I = ½mr²) rolling with speed v is:

  49. 49. The rotational kinetic energy of a hoop (I = mr²) rolling with speed v is:

  50. 50. When a disc rolls down an incline of height h without slipping, its potential energy (mgh) is converted into:

  51. 51. For a disc rolling down an incline, the final speed v is related to height h by:

  52. 52. For a hoop rolling down an incline, the final speed v is related to height h by:

  53. 53. Which object rolls faster down an incline, a disc or a hoop of the same mass and radius?

  54. 54. Artificial satellites are held in orbit around the Earth primarily by:

  55. 55. For a satellite in a stable circular orbit, the required centripetal force is provided by:

  56. 56. The critical velocity (v) required to put a satellite into a low Earth orbit (radius R, acceleration g) is approximately:

  57. 57. The critical velocity for a low Earth orbit is approximately:

  58. 58. As the altitude (h) of a satellite's orbit increases, its required orbital speed:

  59. 59. As the altitude (h) of a satellite's orbit increases, its orbital period (T):

  60. 60. The 'real weight' of an object is defined as the:

  61. 61. The 'apparent weight' measured by a spring balance can differ from the real weight in a(n):

  62. 62. If a lift accelerates upwards with acceleration 'a', the apparent weight (T) of an object inside is:

  63. 63. If a lift accelerates downwards with acceleration 'a', the apparent weight (T) of an object inside is:

  64. 64. If a lift is in free fall (a = g), the apparent weight (T) of an object inside is:

  65. 65. Objects appear weightless inside an orbiting satellite because the satellite and everything in it are:

  66. 66. Artificial gravity can be created in a spaceship by:

  67. 67. The 'floor' of a rotating spaceship provides the necessary ___ force to keep inhabitants moving in a circle.

  68. 68. To simulate Earth's gravity (g) in a spaceship of radius R rotating with frequency f, the required frequency is:

  69. 69. A geostationary satellite orbits the Earth:

  70. 70. A geostationary satellite remains above the same point on the Earth's:

  71. 71. The orbital radius (from Earth's center) for a geostationary satellite is approximately:

  72. 72. How many correctly positioned geostationary satellites are needed to cover the whole populated Earth for communication?

  73. 73. Communication satellites typically operate using:

  74. 74. According to Newton's view, gravitation is:

  75. 75. According to Einstein's theory of General Relativity, gravity is explained as:

  76. 76. In Einstein's view, objects move along ___ in curved space-time.

  77. 77. Einstein's theory predicted that gravity should bend light ___ as much as Newton's particle theory of light predicted.

  78. 78. The bending of starlight by the Sun, confirming Einstein's prediction, was famously observed during a:

Short Answer Questions

Provide your answers in the text boxes below.