Answer:
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

Where,
=mass of man
=mass of stone
=velocity of man
=velocity of stone
Put the value in the equation
As the stone is away from the man
So, the speed of stone is zero



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