A football is kicked with speed U ms−1U \text{ ms}^{-1}U ms−1 from a point A A\,A on a roof, 15 m above the level ground. The ball is projected at an angle of 30∘ 30^\circ\,30∘ above the horizontal. The point B B\,B is the greatest height reached by the ball, which is 8 m vertically above AAA.
Find the value of UUU.
Find the horizontal distance travelled by the ball before it hits the ground.
Find the speed of the ball when it hits the ground.