Approximately

what percentage of the ball’s initial kinetic energy (before the bounce) is the

ball’s final kinetic energy (after the bounce)? Give your answer to the nearest

whole number in units of %. Write your answer without units i.e., 12 % as 12.

Question 4 c)

Immediately

Question 4 b)

If

the ball accelerates uniformly when it hits the floor, calculate its

acceleration as it comes to rest before rebounding. Give your answer to the

nearest whole number in units of m/s

Question 4 a)

As

a tennis ball bounces on a hard surface, it undergoes deformation, compressing

and then rebounding. A tennis ball of mass 57.0 g is dropped from a height of

2.4 m onto a concrete surface and rebounds to a height of 1.35 m. During

impact, the ball compresses by approximately 5 mm. Ignore the effects of air

resistance.

How

fast is the ball moving when it hits the concrete surface?

Question 3 c)

The

batters’ muscles must provide the energy taken to swing the bat from rest. If

we model the batter’s swing as having an average speed of 18 m/s over a swing time

period of 200 ms, what is the power output required by the batters’ muscles to

achieve this swing? (Assume 100% of the energy from her muscles is transferred

to the bat.)

Question 3 b)

If

the softball and bat are in contact for 10 ms, what is the average force that

the bat exerts on the ball?

Question 3 a)

A

fastpitch softball player swings her 600 g bat with a speed of 25 m/s at the

time of impact with the ball. She hits a 170 g softball that was approaching

her at a speed of 30 m/s. The ball rebounds at 41 m/s.

How

fast is her bat moving immediately after the impact? (Ignore the interaction

with her hand for the duration of the collision.)

Question 2 d)

Question 2 c)

Question 2 b)

The

sweepers in a curling competition adjust the