A uniform beam AB AB\,AB of length 10 m and mass 20 kg is used as a ladder. End A A\,A is on rough horizontal ground and the beam rests in limiting equilibrium against a smooth horizontal rail at point CCC, where AC=8AC = 8AC=8 m. The beam is inclined to the horizontal at an angle α\alphaα, where tanα=15/8\tan \alpha = 15/8tanα=15/8. The coefficient of friction between the beam and the ground is μ\muμ.
Find the value of μ\muμ.
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.