Question

A child drops a coin from the top of a building which is 50m high calculate the velocity of a coil when it falls through 20 m distance

Answer 1

Velocity,= d×t
50×20=1000m/s 
Is the velocity

Answer 2

14mpersec
$v ^{2} = u ^{2} + 2gs \\v ^{2} = \ 0 + 2 \times 9.8 \times 20 \\ v ^{2} = 196 \\ v = 14m \: per \: sec$