A child bounces a 56 g superball on the sidewalk. the velocity change of the superball is from 20 m/s downward to 13 m/s upward.
if the contact time with the sidewalk is 1 800 s, what is the magnitude of the average force exerted on the superball by the sidewalk? answer in units of n.
At the top of a pendulum's swing, the ball is no longer moving (at that very specific point of time). All of its kinetic energy has been converted to potential energy (or more specifically in this instance, gravitational potential energy).