Question

A cricket ball is dropped From a height of 20m. Calculate the speed of the ball when it hits the ground. calculate the time it takes to fall through this height. (g = 10m/s²)

Answer 1

(i)s=20m

u=0m/s

a=10m/s^2

using third law of motion

v^2=u^2+2as

v^2=2(10)(20)

v^2=400

v=20m/s

(ii) using first law of motion,

v=u+at

20=0+10t

t=20/10

t=2s