In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
A particle is projected from a point O O\,O on horizontal ground with speed 21 m s−1^{-1}−1 at an angle θ \theta\,θ above the horizontal.
Air resistance is modelled as negligible. The particle passes through the point which is 20 m horizontally and 5 m vertically from OOO.
By writing down expressions for the horizontal and vertical displacements of the particle in terms of t t\,t and eliminating ttt, find the two possible values of θ\thetaθ.
91 exam-style questions on OCR (MEI) A Level Maths 3.3 Projectiles (A-level only), covering 3.3.1 Model motion under gravity using vectors (A-level only), 3.3.2 Position, velocity, range and maximum height (A-level only), 3.3.3 Find the initial velocity of a projectile (A-level only), 3.3.4 Equation of the trajectory (A-level only), and 3.3.5 Solve simple projectile problems (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.