Question

A 81 kg man lying on a surface of negligible friction shoves a 79 g stone away from himself, giving it a speed of 4.5 m/s. What speed does the man acquire as a result?

Answer 1

The speed of the man is 4.54 m/s.

Step-by-step explanation:

Given that,

Mass of man=8100 g

Mass of stone = 79 g

Speed = 4.5 m/s

We need to calculate the speed of the man

Using momentum of conservation

`(m_(1)+m_(2))V=m_(1)v_(1)+m_(2)v_(2)`

Where,

`m_(1)`=mass of man

`m_(2)`=mass of stone

`v_(1)`=velocity of man

`v_(2)`=velocity of stone

Put the value in the equation

As the stone is away from the man

So, the speed of stone is zero

`8179*4.5=8100* v+0`

`v=(8179*4.5)/(8100)`

`v = 4.54\ m/s`

Hence, The speed of the man is 4.54 m/s.