Question 26
A plank ABABAB, of length 2 m and mass M M\,M kg, rests with the end A A\,A against a rough vertical wall. The plank is held in a horizontal position by a rope attached to B B\,B and to the wall at the point CCC.
A small block of mass 2M 2M\,2M kg is placed on the plank at PPP, where AP=1.5AP = 1.5AP=1.5 m. The angle between the rope and the plank is α\alphaα, where tanα=34\displaystyle \tan\alpha = \frac{3}{4}tanα=43.
The plank is modelled as a uniform rod, the block as a particle and the rope as a light inextensible string.
a.[3]
Find, in terms of M M\,M and ggg, the tension in the rope BCBCBC.
b.[3]
Find the direction of the force exerted on the plank at AAA.
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.