Question

A 10-gram rubber ball was launched at a wall several times. The speed of the ball was measured after it hit the wall and bounced off. The force that the ball applied to the wall was also measured. The table below shows the data collected during the investigation.

Force Investigation Data
Force on Wall Return Speed after Bounce
0.5 N 5 m/s
1.5 N 9 m/s
2.0 N 18 m/s

According to the data, what happens to the ball when it applies more force to the wall?
A.
The wall pushes back on the ball with more force, which causes the return speed of the ball to increase.
B.
The ball's return speed decreases because the balanced forces cancel each other out.
C.
The ball's return speed increases because balanced forces cause motion.
D.
The wall pushes back on the ball with less force, which causes the return speed of the ball to decrease.

Answer 1

A.

The data show that larger forces on the wall correspond to larger return speeds (0.5 N → 5 m/s, 1.5 N → 9 m/s, 2.0 N → 18 m/s). By Newton's 3rd law the wall pushes back on the ball with an equal and opposite force; a larger push from the wall produces a greater change in momentum (bigger impulse), so the ball leaves with a higher speed.