A sledge of mass 15 kg is at rest on a rough horizontal patch of ice. The coefficient of friction between the sledge and the ice is 0.2. A child pulls the sledge with a force of F F\,F N at an angle of 30∘ 30^\circ\,30∘ to the horizontal. The sledge is on the point of sliding.
Find the value of FFF.
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.