A book press has a rigid lever that turns about a fixed pivot. The pages provide the same load each time the press is used. A person can push down at an inner grip or at an outer grip. The inner grip is closer to the pivot.
Why is a greater force needed when the person pushes at the inner grip?
Part of the force acts through the pivot at the inner grip, so less of the force produces a turning effect
The force has a smaller perpendicular distance from the pivot, so the moment of the load on the lever becomes larger
The load from the pages acts further from the pivot when the inner grip is used, so its moment increases
The force has a smaller perpendicular distance from the pivot, so a greater force is needed to produce the required moment
124 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.