Q. A ball is dropped from a height of 20 cm. Ball rebounds to a height of 10 cm. What is the loss of energy?
A) 25%
B) 75%
C) 50%
D) 100%
Explanation
(c) $K_{1} = mgh_{1},\ K_{2} = mgh_{2}$
% Loss $= \frac{K_{1} - K_{2}}{K_{1}} \times 100$
$= \frac{h_{1} - h_{2}}{h_{1}} \times 100 = 50\%$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.