A 90 kg man is standing still on frictionless ice. His friend tosses him a 10 kg ball, which has a horizontal velocity of 20 m/s. After catching the ball, what is the man's velocity?

on the glassy ice, a 70 kg skater sits. He propels himself forward by shooting a 3 kg ball horizontally at a pace of 8 m/s. After shooting the puck, how fast can the skater move? The coefficient of friction between the ice and the skated is f = 0.02.

A 56 g base ball is travelling at 40 m/s.  When it hits with the baseball bat, you exert an average force of 78 N, sending the ball back at 30 m/s. How long was the baseball in contact with the bat? Please answer in m/s

Three carts are moving on a frictionless horizontal track as shown in the figure.  The 4.00 kg cart is moving to the right with a speed of 7.0 m/s, the 10.0 kg cart is also moving to the right with a speed of 6.0 m/s while the 3.00 kg cart moves to the left with a speed of 7 m/s.  Find the final speed of the carts when they are all stuck together.   Hint:  The order at which the carts stick together does not matter.  Can you see why?