Choose the best answer

  1. The SI unit of measurement for work is
    1. Coloumb
    2. Joule
    3. Volt
    4. Pascal
    5. Newton
    Answer: B

  2. An object is displaced by a distance of 35 m horizontally
    by a 500 force that makes an angle of 60 deg with the
    horizontal. Calculate the wrk done by the force.
    1. 5323.423 J
    2. 10985.279 J
    3. 8750 J
    4. 11919.385 J
    5. 3630.773 J
    Answer: C

  3. An object is being pulled to the left by a 160 N force
    that makes an angle of 30 deg with the horizontal-left
    while moving to the right for a distance of 70 m.
    Calculate the work done by the force.
    1. -9699.485 J
    2. -7759.588 J
    3. 7759.588 J
    4. -11639.381 J
    5. 9699.485 J
    Answer: A

  4. A 5 kg object is displaced to the right by a distance of 14 m under
    the influence of the following forces: a 40 N
    vertical force pushing on the object downwards, a 2 N force that makes
    an angle of 40 deg with the horizontal-right.
    Calculate the net work done on the object.
    1. 27.157 J
    2. 6.933 J
    3. 4.735 J
    4. 21.449 J
    5. 32.024 J
    Answer: D

  5. Calculate the kinetic energy of an object of
    mass 24.554 kg moving with a speed of 12 m ⁄ s.
    1. 2446.516 J
    2. 3003.533 J
    3. 434.967 J
    4. 1767.888 J
    5. 1555.816 J
    Answer: D

  6. Under the influence of some forces, the speed of
    a 18 kg object changed from 85 m ⁄ s to 100 m ⁄ s.
    Calculate the net work done by the forces.
    1. -24975 J
    2. 24975 J
    3. 29970 J
    4. 19980 J
    5. -19980 J
    Answer: B

  7. Which of the following statements is not correct?
    1. The work done by a conservative force depends only
      on the potential energy of the object at the
      initial and final locations of the object.
    2. Work done by a conservative force in a closed
      path is zero.
    3. Work done by a conservative force does not
      depend on the path followed.
    4. Work done by a conservative force is equal to
      the negative of the change in the potential
      energy of the object.
    5. Work done by a conservative force is equal to
      the change in kinetic energy of the object.
    Answer: E

  8. An object is displaced 3 m by a 64 N conservative
    force that makes an angle of 20 deg with the
    displacement. Calculate the change in its potential energy.
    1. -180.421 J
    2. 180.421 J
    3. -198.463 J
    4. -216.505 J
    5. 198.463 J
    Answer: A

  9. An object has a kinetic energy of 100 J as it crosses
    a location where its potential energy is 5 J.
    Calculate its mechanical energy as it crosses this location.
    1. 105 J
    2. 126 J
    3. 63 J
    4. 85.5 J
    5. 95 J
    Answer: A

  10. Under the influence of conservative forces only,
    an object is displaced from point A to point B.
    Its potential energy and kinetc energy at point A are
    respectively 68.222 J and 50.541 J. Its kinetic energy at point B is
    25 J. Calculate its potential energy at point B.
    1. 58.322 J
    2. 158.781 J
    3. 27.113 J
    4. 93.763 J
    5. 171.235 J
    Answer: D

  11. Under the influence of conservative forces only,
    an object of mass 5 kg is displaced from
    point A to point B. Its potential energy and speed at point A
    respectively are 950 J and 14 m ⁄ s. Its potential energy at point B is -400 J.
    Calculate its speed at point B.
    1. 27.129 m ⁄ s
    2. 48.549 m ⁄ s
    3. 3.32 m ⁄ s
    4. 15.991 m ⁄ s
    5. 32.404 m ⁄ s
    Answer: A