Question

please explain me how the answer is 15m/s

A ball is thrown vertically upwards from the ground. It crosses a point at height of 60 m twice at an interval of 4 s. The velocity with which ball will hit the ground is 40 m/s 20 m/s 30 m/s 15 m/s​

Answer 1

Answer:

30m/s

Explanation:

if it crosses twice 60m distance in 4s then the total distance will be 120m

so speed = distance /time= 120/4=30m/s