A ball impinges directly on another ball at rest. The first ball is brought to rest by the impact. If half of the kinetic energy is lost by the impact, the value of coefficient of restitution is

Options

A. `1//sqrt(2)`
B. `1//2`
C. `1//3`
D. zero

Answer

C

Explanation

Let `m_1 and m_2` be masses of the two balls & u & v are initial and final velocities.
`implies m_1u = m_2v and 1/2 m_2v^2 = 1/3 cdot 1/2 m_1 u^2 implies v = 1/3 u implies e = 1/3`.