Question

A ball is dropped from the top of the building 19.6 m high find the time taken by ball

Answer 1

Answer:

The required time taken by the ball to reach the ground is 2 seconds.

Explanation:

Given :

A ball is dropped from the top of the building 19.6 m high

To find :

the time taken by the ball to reach the ground

Solution :

As the ball is dropped, the initial velocity of the ball is 0 m/s.

i.e., u = 0 m/s

acceleration due to gravity, a = g = 9.8 m/s²

height of the building, h = 19.6 m

time taken, t = ?

Using  $\underline{\bf s=ut+\dfrac{1}{2}at^2}$ ,

$\rm 19.6 =(0)t+\dfrac{1}{2}(9.8)(t^2) \\\\ \rm 19.6 =0+4.9t^2 \\\\ \rm t^2=\dfrac{19.6}{4.9} \\\\ \rm t^2=4 \\\\ \rm t=\sqrt{4} \\\\ \bf t=2 \ sec$

Therefore, the time taken by the ball to reach the ground is 2 seconds.