Question

A ball of mass 0.1 kg, initially at rest, is dropped from height of 1 m. ball hits the ground and bounces off the ground. upon impact with the ground, its velocity reduces by 20%. the height (in m) to which the ball will rise is:

Answer 1

v when it touches the surface
V=root(2×10×1)
=2root5
v when it bounces back
v=V-V/5
v=4V/5
v=8/5(root5)
h=v^2/2g
=(64×5)/(25×2×10)
=0.64m