Question

a boy standing at the top of a tower of 20m height drops a stone. assuming g= 10m/s², the velocity with which it hits the ground is?

Answer 1

h = 20m
g = 10m/s²
u = 0m/s (since the stone was initially at rest)

using third equation ,

v² = u²+2gh
=> v² = 0² + 2(10)(20)
=> v² = 400

=> v = √400 => 20m/s



hope this helps

Answer 2

For freely falling object
u = 0

v = √(2gH)
= √(2 × 10 m/s² × 20 m)
= 20 m/s

Velocity when it hits the ground is 20 m/s