Question

A boy stands 39.2 metre distance from a building can throw a ball with just passes through window 19.6 m above the ground calculate velocity of projection

Answer 1

According to an equation of motion, we have that: s=ut+at²/2
a=accelarationt = time 
and v is the velocity

39.2-19.6=v+10/2×1²19.6=v+519.6-5=v14.6=v
velocity is 14.6 m/s
hope this helps u