In this question use g=9.81 m s−2g = 9.81 \text{ m s}^{-2}g=9.81 m s−2.
A specialized fire-suppressant canister is launched from a mobile unit positioned on a hilltop. The canister is projected from a point AAA with an initial speed uuu at an angle of 25∘25^\circ25∘ above the horizontal.
The canister hits its target at point BBB, which is located in a valley 22 metres vertically below the level of launch at AAA.
It is observed that the canister takes 1.8 seconds to reach the peak of its trajectory.
Calculate the value of uuu.
Determine the total time elapsed from the moment of launch until the canister strikes its target at point BBB.
260 exam-style questions on OCR A Level Maths 3.2 Kinematics, covering 3.2.1 Language of kinematics, 3.2.2 Graphs in kinematics, 3.2.3 Displacement-time and velocity-time graphs, 3.2.4 Constant acceleration formulae, 3.2.5 Constant acceleration in two dimensions (A-level only), 3.2.6 Non-uniform acceleration in one dimension (A-level only), 3.2.7 Non-uniform acceleration in two dimensions (A-level only), 3.2.8 Motion under gravity using vectors (A-level only), and 3.2.9 Projectiles (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.