Question

The two diagrams show the situation before and after a collision between two spheres $A$ and $B$ of equal radii moving along the same straight line on a smooth horizontal surface. The coefficient of restitution $e$ is

• A. $\frac{2}{3}$
• B. $\frac{1}{2}$
• C. $\frac{1}{3}$
• D. $\frac{1}{4}$

Answer 1

Answer: (B)

$e=\frac{v_{s e p}}{v_{a p p}}=\frac{v_{2} - v_{1}}{u_{1} - u_{2}}$
$u_{1}=8 \, m \, s^{- 1},v_{1}=2 \, m \, s^{- 1}$
$u_{2}=2 \, m \, s^{- 1},v_{2}=5 \, m \, s^{- 1}$