Question

Two balls a and b have the same mass and diameter but are made from differenttypes of ribber the ballare dropped from the same height above the floor after collidong with the floor ball a bounches higher than ball bbounches. Which of the following quantities must necessarily be larger for ball a than ball b?
a. The momentum just before colliding with the floor.
b. The amount of time in contact with the floor.
c. The kinetic energy just before colliding with the floor.
d. The average force exerted by the floor
e. The impulse exerted by the floor

Answer 1

Answer:

e. The impulse exerted by the floor

Explanation:

a. The momentum just before colliding with the floor.

will be identical because they have the same mass and are falling the            same distance so will have the same velocity.  p = mΔv,   v = √(2gh)

b. The amount of time in contact with the floor.

a component of impulse, but not the entire story. Ball B could have a longer contact time, but a smaller average force.  p = FΔt

c. The kinetic energy just before colliding with the floor.

will be identical because they have the same mass and are falling the            same distance so will have the same velocity.  KE = ½mv²,   v = √(2gh)

d. The average force exerted by the floor

a component of impulse, but not the entire story. ball B could have a larger average force but a shorter period of action.  p = FΔt