Question 17
In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
A ladder AB AB\,AB has length 5 m and mass 10 kg. The end A A\,A rests on rough horizontal ground and the ladder rests in limiting equilibrium against a fixed smooth horizontal rail at the point CCC, where AC=4AC = 4AC=4 m.
The vertical plane containing AB AB\,AB is perpendicular to the rail. The ladder is inclined to the horizontal at an angle α\alphaα, where tanα=125\displaystyle \tan\alpha = \frac{12}{5}tanα=512. The ladder is modelled as a uniform rod, and the coefficient of friction between the ladder and the ground is μ\muμ.
Using this model, find the value of μ\muμ.
3.3 R: Forces and Newton's laws Questions
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.