Question

A ball is dropped on to a horizontal plate from a height h = 9 m above it. If the coefficient of restitution is e = $1/2$, the total distance travelled before the ball comes to rest is

• A. 10 m
• B. 15 m
• C. 20 m
• D. 25 m

Answer 1

The correct option is B 15 m

In case of rebound, we have the total distance traveled as :

$d=h\left(\frac{1+e^2}{1-e^2}\right)$

$d=9\left(\frac{1+{0.5}^2}{1-{0.5}^2}\right)$

$d=9\left(\frac{1.25}{0.75}\right)m$

$d=9\times \frac{5}{3}m$

$d=15m$