A stage technician uses a light horizontal control lever pivoted at a fixed point. A sandbag of mass 18 kg hangs from the lever 0.25 m to the right of the pivot. A cable pulls downwards with a force of 90 N, 0.50 m to the right of the pivot. The technician applies a downward effort 1.20 m to the left of the pivot.
The gravitational field strength is 10 N/kg.
Calculate the effort needed to keep the lever in rotational equilibrium.
The technician applies an effort of 60 N instead. Explain which way the lever starts to turn.
102 exam-style questions on Edexcel GCSE Physics 9.2 Moments, covering 9.2.1 Rotational effects of forces and moments, 9.2.2 The principle of moments, and 9.2.3 Levers and gears. Each one has a worked solution and a mark scheme showing where the marks go.