1. A 50kg girl throws a 7kg medicine ball at 10m/s to a 40kg boy. If both are on a frictionless frozen lake, what are both the children's recoil velocities?
2. A 0.6kg basketball strikes the floor at 6m/s and rebounds at 5.2m/s. If it is in contact with the floor for 0.12 seconds, what is the average force on the ball?
3. A 0.2kg mass moves in a 0.5m radius circular path with an angular velocity of 2rad/s. What is the new angular velocity of the mass when the string is moving in a 0.2m radius circular path?
