The solid rubber balls A and B having masses 200 and 400 gm respectively are moving in opposite directions with velocity of A equal to 0.3 m / s . After collision the two balls come to rest, then the velocity of B is

Options

A. 0.15 m/sec
B. 1.5 m/sec
C. `-0.15 m/sec
D. None of these

Answer

A

Explanation

`m_(1)` =0.2 kg, ,`m_(2)`=0.4 kg, `v_(1)`=0.3/s,`v_(2)`=?
Applying law of conservation of momentum
`m_(1)v_(1)m_(2)v_(2)=(0.2xx0.3)/(0.4)=0.15 m//s`