A body of mass `m_(1)` moving with a velocity `3 m//s` collides with another body at rest of `m_(2)` . After collision the velocities of the two bodies are `2 m//s` and `5 m//s` , respectively , along the direction of motion of `m_(1)`. The ratio `m_(1)//m_(2)` is

Options

A. `(5)/(12)`
B. 5
C. `(1)/(5)`
D. `(12)/(5)`

Answer

B

Explanation

If target is at rest then final velocity of bodies are
`v_(1) = ((m_(1)-m_(2))/(m_(1) + m_(2))) u_(1)` (i) and `v_(2)= (2m_(1)u_(1))/(m_(1) + m_(2))` …(ii)
From (i) and (ii) `(v_(1))/(v_(2))= (m_(1)-m_(2))/(2m_(1)) = (2)/(5) rArr (m_(1))/(m_(2))= 5`