Question

A body of mass is 10kg dropped to the height 20metre. What is the final velocity and time taken to drop the ground.

Answer 1

Answer:20 m/s

Explanation: we have,

V^2 = u^ + 2gs

Or v^2 = 2 gs

v^2 = 400

Hence, v= 20 m/s

Answer 2

Answer:

By applying the third equation of motion

Since the initial velocity of the body is zero during free fall

s=ut + 1/2gt^2

20=0+ 1/2 ×10×t^2

20=5t^2

t^2=4

t=2

t=2s, u=0m/s , a =10m/s^2

By applying newton first law of motion

v=u + at

v=0 + 10×2

v=20m/s