Question

A body of MASS OF 2KG FALLS FREELY FROM REST THROUGH A HEIGHT OF 50M AND COMES TO REST HAVING PENETRATE 5.0CM OF SAND CALCULATE THE TIME TAKING IN FALLING

Answer 1

50 = 1/2 g t^2 ... t = √(100 / 9.8)

Answer 2

Still has to go through the sand though.
It hits the top of the sand in the time R Scott gave you.
How long now until it stops?
assume constant deacceleration in the sand
need speed at sand top
(1/2) m v^2 = m g h
v ^2 = 2 * 9.8 * 50 = 980
v = 31.3 m/s at sand top
average speed during stop = 31.3/2 = 15.7 m/s
time to go 5 cm or 0.05 meters = 0.05 /15.7 = .0032 seconds
not long :)