A uniform plank of wood has a weight of 150 N and a length of 3.0 m. The plank rests on a single pivot placed 1.0 m from its left hand end. A child stands on the left hand end of the plank.
Give the distance between the pivot and the centre of mass of the plank.
Calculate the moment of the weight of the plank about the pivot.
Calculate the smallest weight of the child that would hold the plank horizontal.
The child then walks slowly towards the pivot. Explain what happens to the plank.
40 exam-style questions on AQA GCSE Physics 5.4 Moments, levers and gears, covering 5.4 Moments, levers and gears. Each one has a worked solution and a mark scheme showing where the marks go.