Practice Quiz 11

Choose the best answer

  1. The momentum of an object wil be conserved if
    1. If the force acting on the bject is a constant.
    2. if all the forces acting on the object are
      conservative.
    3. if the object changes it velocity uniformly.
    4. if the mechanical energy of the object is
      conserved.
    5. the net force acting on the object is zero.
    Answer: E

  2. Calculate the impulse impacted on an object which
    has been acted upon for 0.25 seconds by a 2 N force.
    1. 0.308 N s
    2. 0.425 N s
    3. 0.5 N s
    4. 0.368 N s
    5. 0.711 N s
    Answer: C

  3. A object of mass 0.2 kg moving to the right with a speed of
    15 m ⁄ s hits a wall and bounces back to the left with a speed of
    9 m ⁄ s. Calculate the change in its momentum.
    1. -7.835 kg m ⁄ s
    2. -4.8 kg m ⁄ s
    3. -1.518 kg m ⁄ s
    4. -6.708 kg m ⁄ s
    5. -0.709 kg m ⁄ s
    Answer: B

  4. An object of mass 0.2 kg falling vertically downward
    hits the ground with a speed of 13 m ⁄ s and bounces
    back vertically upward with a speed 2 m ⁄ s. If the object was in
    contact with the ground for 0.2 seconds, calculate the
    average force exerted by the ground on the object.
    1. 23.131 N
    2. 15 N
    3. 8.288 N
    4. 26.002 N
    5. 10.668 N
    Answer: B

  5. An object was acted upon by a force of 3 for 0.9
    seconds. Calculate the change in its momentum.
    1. 4.287 kg m ⁄ s
    2. 1.377 kg m ⁄ s
    3. 1.716 kg m ⁄ s
    4. 2.7 kg m ⁄ s
    5. 0.906 kg m ⁄ s
    Answer: D

  6. An object of mass 2.5 kg was acted by a force of 10.2 N for
    4.8 seconds. If its initial speed was 2.4 m ⁄ s,
    calculate its final speed.
    1. 8.616 m ⁄ s
    2. 35.397 m ⁄ s
    3. 21.984 m ⁄ s
    4. 14.113 m ⁄ s
    5. 32.766 m ⁄ s
    Answer: C

  7. An object of mass 4 kg moving with a speed
    of 24 m ⁄ s to the right collides with an object
    of mass 11 kg moving with a speed of 12 m ⁄ s
    in the same direction. After collision, the 4 kg object moves
    to the right with a speed of 5 m ⁄ s to the right. Calculate
    the velocity of the 11 kg object after collision.
    1. 24.582 m ⁄ s
    2. 11.345 m ⁄ s
    3. 15.127 m ⁄ s
    4. 20.8 m ⁄ s
    5. 18.909 m ⁄ s
    Answer: E

  8. An object of mass 14 kg moving with a speed
    of 25 m ⁄ s to the right collides with an object
    of mass 11.5 kg moving with a speed of 10 m ⁄ s
    to the left. After collision, the 11.5 kg object moves
    to the right with a speed of 10 m ⁄ s to the right. Calculate
    the velocity of the 14 kg object after collision.
    1. 3.086 m ⁄ s
    2. 6.177 m ⁄ s
    3. 8.571 m ⁄ s
    4. 9.438 m ⁄ s
    5. 13.369 m ⁄ s
    Answer: C

  9. An object of mass 18 kg moving with a speed
    of 30 m ⁄ s to the right collides with an object
    of mass 15 kg moving with a speed of 16 m ⁄ s
    to the left. If the collision is completely inelastic,
    calculate their speed after collision.
    1. 10.214 m ⁄ s
    2. 9.091 m ⁄ s
    3. 12.748 m ⁄ s
    4. 6.527 m ⁄ s
    5. 13.447 m ⁄ s
    Answer: B

  10. An object of mass 12 kg moving with a speed
    of 27 m ⁄ s to the right collides with an object
    of mass 21 kg at rest. If the collision is completely inelastic,
    calculate the kinetic energy lost during the collision.
    1. -1851.685 J
    2. -393.101 J
    3. -2350.499 J
    4. -871.481 J
    5. -2783.455 J
    Answer: E