Q 11-05-024NEETEAMCET 2012 (Medical)Easy
A ball at rest is dropped freely from a height of $20$ m. It loses $30\%$ of its energy on striking the ground and bounces back. The height to which it bounces back is
Answer: (A) $14$ m
Concept. Kept energy becomes PE at the top of the bounce.
Step 1. Height. $0.7 \times 20 = 14$ m.
Answer. $14$ m (Option A).
Solution by Sreeraj P, M.Sc Physics