Question

A stone is let to fall vertically down from a window on the 10^th floor of a building 40m above the ground. Find the time taken by the stone to reach the ground. 

Answer 1

u = 0
s = 40
g = 10m/s²
S = ut + ½ gt^2
40/₅=0×t×½×10×t²
= 2.46 s