Two crates A A\,A and BBB, of mass 5 kg and 4 kg respectively, are connected by a light inextensible rope that passes over a smooth pulley at the top of a symmetrical wedge. The wedge is fixed to the floor, with both faces inclined at an angle of 45∘ 45^\circ\,45∘ to the horizontal. Crate A A\,A is on a smooth face, while crate B B\,B is on a rough face where the coefficient of friction is 0.2. The rope remains taut throughout the motion.
Find the tension in the rope.
Find the acceleration of the system and the direction of travel.
139 exam-style questions on AQA A Level Maths 3.3 R: Forces and Newton's laws, covering 3.3.1 Concept of a force and Newton's first law, 3.3.2 Newton's second law, 3.3.3 Weight and motion under gravity, 3.3.4 Newton's third law and equilibrium, 3.3.5 Addition of forces and resultants (A-level only), and 3.3.6 Friction (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.