Question

A stone is dropped from a height h,then time taken to reach ground is?

Answer 1

Given :

The height from which the stone is dropped = h

Acceleration due to gravity experienced = g

Initial velocity , u = 0

To find :

The time taken by the stone to reach on the ground .

Solution :

Let the time taken by the stone to reach the ground be t .

By using 2nd equation motion ,

     distance = initial velocity * time taken + (1/2) * acceleration * time * time

=>  -h = u * t - (1/2) * g * t * t

( minus sign for height and g as per convention )

=>  -h = - (1/2) * g * t * t

=>  t = $\sqrt[]{2*h/g}$

$\sqrt[]{2*h/g}$ is the time taken by the stone to reach on the ground .