Let a projectile be projected with speed 'u' at angle 'θ' from O and strike the ground at P with velocity 'v'.
The projectile will strike the ground at P after time equal to the time of the flight.
Now, resolving the components of 'u' in the horizontal and vertical direction, we have
Horizontal and vertical component is given by,
Therefore magnitude of velocity at ground is,
Therefore to hit the target one has to aim a little above as shown in figure (ii), so that after following the parabolic path, the bullet may hit the target.