A body of mass `m_(1) ` moving with uniform velocity of 40 m/s collides with another mass `m_(2)` at rest and then the two together begin to moe wit h uniform velocity of 30 m/s. the ratio of their masses `(m_(1))/(m_(2))` is

Options

A. 0.75
B. 1.33
C. `3.0`
D. `4.0`

Answer

C

Explanation

By conservation of momentum:
`m_(1) (40) = (m_(1) + m_(2))30`
`40/30 =1 + m_(2)/m_(1)`
`m_(1)/m_(2) = 30/10 = 3`