Water leaves the end of a hose pipe at point P with a horizontal velocity of 
.
Point P is at height 
above the ground. The water hits the ground at point Q. The horizontal distance from P to Q is 
.
Air resistance is negligible. Assume that the water between P and Q consists of non-interacting droplets of water and that the only force acting on each droplet is its weight.
Explain, briefly, why the horizontal component of the velocity of a droplet of water remains constant as it moves from P to Q.
Show that the time taken for a droplet of water to move from P to Q is 
.
Calculate height .
.
.
