Two particles P P\,P of mass 4 kg and Q Q\,Q of mass 3 kg are connected by a light inextensible string. The string passes over a smooth pulley fixed at the apex of a wedge. One face of the wedge is smooth and inclined at an angle of 60∘ 60^\circ\,60∘ to the horizontal. The other face of the wedge is rough and inclined at an angle of 30∘ 30^\circ\,30∘ to the horizontal. P P\,P lies on the smooth face and the string connecting the particles is taut. The coefficient of friction between Q Q\,Q and the rough face is 0.25.
Find the tension in the string.
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.