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A man (mass = 50 kg) and his son (mass =...

A man (mass = 50 kg) and his son (mass = 20 kg) are standing on a frictionless surface facing each other. The man pushes his son so that he starts moving at a speed of `0.70 m s^(-1)` with respect to the man. The speed of the man with respect to the surface is:

A

`0.20 ms^(-1)`

B

`0.14 ms^(-1)`

C

`0.47 ms^(-1)`

D

`0.28 ms^(-1)`

Text Solution

Verified by Experts

The correct Answer is:
A
`P_(i) = 0`
`P_(f) = 20(0.7-v)- 50(v))`
`P_(i) = P_(f) `14-20v = 50v rArr 14 = 70v rArr v = 14/70 = 0.2 m//s`
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