Grade 12 Physics: Momenta and Collisions

A 0.75 kg ball rolls toward a stationary 0.5 kg ball with a speed of 2 m/s. After an elastic collision, the 0.75 kg ball comes to a complete stop. Calculate the speed of the 0.5 kg ball immediately after the collision.

A 70 kg ice skater traveling at 8 m/s collides with a 60 kg skater moving in the opposite direction at 5 m/s. After the collision, they move together as one unit. Calculate their final velocity.

A 0.2 kg ball is thrown at a wall with a speed of 10 m/s. It rebounds with a speed of 8 m/s in the opposite direction. If the contact time with the wall is 0.05 s, calculate the average force exerted by the wall on the ball.