A window cleaner's ladder AB AB\,AB has a mass of 15 kg and a length of 6 m. The ladder is modelled as a uniform rod. It rests with its lower end A A\,A on a rough horizontal pavement and its upper part against a smooth horizontal rail at point CCC. Given AC=5AC = 5AC=5 m and the ladder is in limiting equilibrium. The ladder makes an angle α \alpha\,α with the horizontal, where tanα=3/4\tan \alpha = 3/4tanα=3/4. The coefficient of friction at the ground is μ\muμ.
Calculate 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.