A rough surface is inclined at an angle θ \theta\,θ to the horizontal, where tanθ=815\displaystyle \tan \theta = \frac{8}{15}tanθ=158. A crate of mass k k\,k kg is placed on the surface and allowed to slide. The coefficient of friction between the crate and the surface is 13\displaystyle \frac{1}{3}31.
Find the acceleration of the crate.
A different crate with mass 5k 5k\,5k kg is placed on the same surface. Explain how the acceleration of this crate would compare to your answer in part (a).
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.