A ball dropped from a height of 2 m rebounds to a height of 1.5 m after hitting the ground. Then the percentage of energy lost is

A ball dropped from a height of 2 m rebounds to a height of 1.5 m afte

1.	A ball dropped from a height of 2 m rebounds to a height of 1.5 m after hitting the ground. Then the percentage of energy lost is
Answer» 25% 30% 50% 100% Solution :`U_1 = mgh_1 and U_2 = mgh_2` % ENERGY LOST = `(U_1 - U_2)/(U_1) xx 100% = (mgh_1 - mgh_2)/(mgh_1) xx 100%` `= ((h_1 - h_2)/(h_1)) xx 100% = (2 - 1.5)/(2) xx 100% = 25%`.