Question

1.Was the mechanical energy of the falling mass conserved?Di

Answer 1

1.If the retarded force can be negligible,mechanical energy of the falling mass conserved.The error source comes from resistance,buoyancy and other similar things.

2.The ball can't rebound to a greater height than its original height because of resistance.If the retarded force can be negligible,the ball only can rebound to its original height.