I need help:

1. A ball with a mass of 10.0 9 hits a 5.0 kg block of wood tied to a string, as shown. You may assume that there is no friction from the string. The ball hits the block in a completely inelastic collision, causing the block to rise to a maximum height of 8.0 cm. Find the initial horizontal speed of the ball. You may assume that the string is very long. 2. A 1.2 kg cart moving at 6.0 m/s [E] collides with a stationary 1.8 kg cart. The head-on collision is completely elastic and is cushioned by a spring. a. Find the velocity of each cart after the collision. b. The maximum compression of the spring during the collision is 2.0 cm. Find the spring constant. 3. A0.50 kg magnetic puck moving at 4.0 m/s [E] is sliding on a frictionless horizontal air table. It undergoes an elastic head-on collision with another magnetic puck of mass 0.90 kg, moving at 3.0 m/s [W]. Find the velocity of each puck after the collision. 4.0m/s[E] 3.0m/s[W]