Question 15
In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
Two particles PPP, of mass 6 kg, and QQQ, of mass 2 kg, are connected by a light inextensible string which passes over a smooth pulley fixed at the top of a wedge.
One face of the wedge is smooth and inclined at 30° 30°\,30° to the horizontal; the other face is rough and inclined at 45° 45°\,45° to the horizontal. P P\,P lies on the smooth face and Q Q\,Q lies on the rough face, with the string taut and parallel to a line of greatest slope of each face.
The coefficient of friction between Q Q\,Q and the rough face is 0.3.
a.[5]
Find the tension in the string.
b.[2]
Find the acceleration of the system, and state the direction in which P P\,P moves.
3.3 R: Forces and Newton's laws Questions
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.