In a soccer game, a 1.3 kg ball is coming straight to a soccer player at a velocity of 13 m/s who then kicks it in the opposite direction at 22 m/s after being in contact with the
ball for 0.04 s. How much force did the soccer player use to kick the ball?

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?