Question

A ball is dropped from a height of 90m. How long it will take to reach the ground

Answer 1

Answer:

4.242 sec

Step-by-step explanation:

S = ut +( 1/2)at^2

S = 90 m

u = 0 as dropped

a = g

90 = (1/2) g t^2

t^2 = 180/g

taking g = 10m/s^2

t^2 = 180/10 = 18

t = 3 root2

t = 3*1.414

t = 4.242 sec