Question

A rubber ball is dropped from a height of $5$cm on a plane, where the acceleration due to gravity is not shown. On bouncing it rises to $1.8$m. The ball loses its velocity on bouncing by a factor of?

• A. $\frac{16}{25}$
• B. $\frac{2}{5}$
• C. $\frac{5}{3}$
• D. $\frac{9}{25}$

Answer 1

The correct option is C $\frac{5}{3}$

$\frac{\frac{1}{2}{{mv}_1}^2}{\frac{1}{2}{{mv}_2}^2}=\frac{mg{h}_1}{mg{h}_2}=\frac{25}{9}$

$\frac{{v_1}^2}{{v_2}^2}=\frac{25}{9}$

$\frac{v_1}{v_2}=\frac{5}{3}$