Question

a stone is dropped from a height of 50 metres. calculate final velocity just before touching the ground.​

Answer 1

Given:-

→Height from which the stone is

dropped = 50m

To find:-

→Final velocity of the stone just before

touching the ground

Solution:-

In this case:-

•Initial velocity(u) of the stone will be zero as it was initially at rest.

•Acceleration due to gravity(g) will be +9.8m/s² as the stone is freely falling.

By using the 3rd equation of motion,we get:-

=>v²-u² = 2gh

=>v²-(0)² = 2(9.8)50

=>v² = 980

=>v = √980

=>v = 31.30m/s. (approximately)

Thus,final velocity of the stone just before touching the ground is

31.30m/s.

Some Extra Information:-

The 3 equations of motion,for a freely falling body are:-

•v = u+gt

•h = ut+1/2gt²

•v²-u² = 2gh