Question

A stone was dropped freely in a river flowing down a bridge. The stone
takes 2 seconds in touching the water surface. The height of the bridge is1)
9.8 m 2) 19.6 m 3) 39.2 m 4) Data inadequate

Answer 1

s = ut + 1/2at²
s = 0(t) + 1/2g(2)²
s = 9.8 x 2
s =19.6m

19.6 m is a correct option