A particle of mass `2kg` moving with a velocity `5hatim//s` collides head-on with another particle of mass `3kg` moving with a velocity `-2hatim//s`. After the collision the first particle has speed of `1.6m//s` in negative x-direction, Find
(a) velocity of the centre of mass after the collision,
(b) velocity of the second particle after the collision.
(c) coefficient of restitution.

Answer

A, B, C, D

Explanation

(a) `v_c=(m_1u_1+m_2u_2)/(m_1+m_2)=0.8hatim//s`
(b) `v_1=-1.6hatim//s`
From COM, `m_1u_1+m_2u_2=m_1v_1_m_2v_2`
`implies v_2=2.4hatim//s`
(c) `e=(v_2-v_1)/(u_1-u_2)=4/7`