Question 13
In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
Two blocks AAA, of mass 2 kg, and BBB, of mass 3 kg, are connected by a light inextensible string.
Initially A A\,A is held at rest on a rough plane inclined at an angle θ \theta\,θ to the horizontal, where tanθ=34\displaystyle \tan\theta = \frac{3}{4}tanθ=43. The string passes over a smooth fixed pulley at the top of the plane, parallel to a line of greatest slope, and B B\,B hangs freely.
The coefficient of friction between A A\,A and the plane is 58\displaystyle \frac{5}{8}85. The blocks are released and A A\,A moves up the plane. The blocks are modelled as particles.
a.[5]
Find the tension in the string.
b.[2]
After B B\,B reaches the ground, A A\,A continues up the plane and comes to rest before reaching the pulley. Determine whether A A\,A remains at rest.
c.[2]
Suggest two refinements to the model that would make it more realistic.
3.4 Forces Questions
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.