Mathematics 9709 · AS & A Level · Newton's laws of motion
Newton's laws of motion — practice question
Particles A and B have masses $0.32\,\text{kg}$ and $0.48\,\text{kg}$ respectively. They are joined by a light inextensible string that passes over a small smooth pulley fixed at the edge of a smooth horizontal table. Particle B is initially at rest on the table, $1.4\,\text{m}$ from the pulley. A is hanging vertically beneath the pulley, with its height $0.98\,\text{m}$ above the floor (see diagram). A, B, the string and the pulley all lie in the same vertical plane. B is released and A moves downwards.
(i)[5]
Find the acceleration of A and the tension in the string.
(ii)[2]
A hits the floor and B continues to move towards the pulley. Find the time taken, from the instant that B is released, for A to reach the floor.
(iii)[3]
Find the time taken, from the instant that B is released, for B to reach the pulley.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Using Newton’s second law for one particle” …