Q. A ball moving with velocity $2\ m/s$. collides head on with another stationary ball of double the mass. If the coefficient of restitution is 0.5, then their velocities (in $m/s$) after collision will be
A) 0, 2
B) 0, 1
C) 1, 1
D) 1, 0.5
Explanation
(b) [image:6_image68.emf]
By conservation of linear momentum
$2m = mv_{1} + 2mv_{2} \Rightarrow v_{1} + 2v_{2} = 2$
By definition of $e,e = \frac{1}{2} = \frac{v_{2} - v_{1}}{2 - 0}$
$\Rightarrow v_{2} - v_{1} = 1 \Rightarrow v_{1} = 0$ and $v_{2} = 1ms^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.