Question

Estimate the height of the bridge over a river a stone is dropped freely in the river from the bridge the stone takes 2 seconds to touch the water surface in the river calculate the height of the bridge from water level (g = 9.8m/s²)​

Answer 1

let the height of the bridge be 'h'

acceleration is g(9.8m/s²)

time is 2sec

using third law of motion

s=ut+1/2gt²

h=0*2+1/2*9.8*2²

h=1/2*9.8*4

h=19.6m