In this question use g=9.81 m s−2g = 9.81 \text{ m s}^{-2}g=9.81 m s−2.
A rescue flare is launched from a point LLL at the edge of a vertical cliff. The initial velocity of the flare is u m s−1u \text{ m s}^{-1}u m s−1 at an angle of 35∘35^\circ35∘ above the horizontal.
The flare reaches its maximum height exactly 1.51.51.5 seconds after launch. It eventually lands in the sea at a point SSS, which is 202020 metres below the level of LLL.
Determine the value of uuu.
Calculate the total time of flight of the flare from launch to landing in the sea.
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.