Question

A ball with a mass 0.5 kg is dropped from a height of 10 m to the ground and bounces back to a height of 7m. How much potential energy does the ball lose

Answer 1

Given:

$m=\rm 0.5 \: kg$

$h_1=\rm 10 \: m$

$h_2=\rm 7 \: m$

The loss in potential energy of the ball

$$\Delta E_p=mg(h_1-h_2)\\ \rm=0.5\: kg*9.8\: N/kg*(10-7)\: m=14.7\: J$$