In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
Two blocks PPP, of mass 5 kg, and QQQ, of mass 3 kg, rest in contact with each other on a rough horizontal floor.
A horizontal force of magnitude 40 N is applied to PPP, pushing both blocks along the floor. The coefficient of friction between each block and the floor is 0.2.
Find the acceleration of the blocks.
Find the magnitude of the force exerted by P P\,P on QQQ.
87 exam-style questions on OCR (MEI) A Level Maths 3.4 Forces, covering 3.4.1 Language relating to forces, 3.4.2 Acceleration due to gravity, 3.4.3 Identify forces and draw force diagrams, 3.4.4 Resultant of concurrent forces, 3.4.5 Equilibrium of a particle, 3.4.6 Resolve a force into components (A-level only), 3.4.7 Equilibrium condition for resultant zero (A-level only), 3.4.8 Forces in equilibrium sum to zero (A-level only), 3.4.9 Equations for a particle in equilibrium (A-level only), 3.4.10 Frictional force and normal contact force (A-level only), 3.4.11 Model friction with F ≤ μR (A-level only), and 3.4.12 Apply Newton's Laws to friction problems (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.