A tennis ball is projected with speed U ms−1U \text{ ms}^{-1}U ms−1 from a point OOO, which is 1.5 m above the horizontal ground. The ball is projected at an angle α∘ \alpha^\circ\,α∘ to the horizontal. During its flight, the ball reaches a maximum height of 4.5 m above the ground and passes through a point AAA, which is 0.5 m above the ground and at a horizontal distance of 12 m from OOO. The ball is modeled as a particle moving under gravity.
Find the value of UUU.
Find the size of angle α\alphaα.
State one limitation of the model that could affect the accuracy of your answers.
