To estimate the height of a bridge over the river, a stone is dropped freely on the river from the bridge. the stone takes 2m/s to touch the water surface in the river. calculate the height of the bridge from water level. (g= 9.8 m/s2)
initial velocity u=0
a=9.8m/s2
final velocity v=2m/s
2as=v2-u2
s=22-0 /2×9.8
=4/19.6
s=0.20m