Question

A ball is thrown upwards and reaches a height of 100 m in 2s. What is its initial speed?

Answer 1

Explanation:

s =100m

v=0m/s

t=2s

Therefore ,

s=ut+1/2at^2

100=2×u+1/2×10×(2)^2

100=2u+1/2×40

100=2u+20

100-20=2u

80=2u......

Therefore ,

u = 40m/s