Q. An elastic ball is dropped from a height $\ h$ and it rebounds many times from the floor .If the coefficient of restitution is e, the times interval between the second and the third impact, is
A) $ev/g$
B) $e^{2}v/g$
C) $e^{2}\sqrt{\left( \frac{8h}{g} \right)}$
D) $e^{2}\sqrt{\left( \frac{h}{g} \right)}$
Explanation
(c) $t = \sqrt{\left( \frac{2h}{g}\ \right)}\ $
The second impact occurs after an additional times
$= 2\sqrt{2h_{1}g}$
$= 2e\sqrt{\frac{2h}{g}}$
The third impact occurs after an additional time
$= 2\sqrt{2h_{2}g}$
$= 2e^{2}\sqrt{\frac{2h}{g}}$
$= e^{2}\sqrt{\frac{8h}{g}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.