A child bounces a 48 g superball on the side- walk. The velocity change of the superball is from 23 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. 015 10.0 points A 0.48 kg football is thrown with a velocity of 18 m/s to the right. A stationary receiver catches the ball and brings it to rest in 0.020 S. What is the force exerted on the receiver? Answer in units of N.