A supply crate is fired from a relief-aid pneumatic launcher positioned on a flat desert plain. The crate leaves the launcher at ground level with an initial speed of U m s−1U \text{ m s}^{-1}U m s−1 directed at an angle θ \theta\,θ above the horizontal. To reach a remote medical camp located a horizontal distance X X\,X away, the crate must travel at least that distance before its first impact with the ground.
By modelling the crate as a particle and assuming constant gravitational acceleration ggg, show that the angle of projection must satisfy:
sin2θ≥XgU2\sin 2\theta \ge \frac{Xg}{U^2}sin2θ≥U2Xg
Practise Edexcel A Level Maths Projectiles with exam-style questions for A Level Maths. 73 questions covering Horizontal Projection, Horizontal and Vertical Components, Projection at Any Angle, and Projectile Motion Formulae, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.