Question

A stone is dropped freely in the river from a bridge. It takes 5 seconds to touch the water surface in the river. Calculate the height of the bridge from the water level. (g=9.8m/s)

Answer 1

Time = 5 seconds
Acceleration = 9.8
Initial velocity = 0
Using s=u +1/2at^2
s = 0 + 1/2x9.8x5^2
s= 122.5 m