A hand-operated can crusher has a rigid handle that turns about a fixed pivot and moves a crushing plate against an empty can. A person pushes perpendicular to the handle but moves their hand from the end of the handle towards the pivot.
Why does moving their hand towards the pivot mean that the person must push with a greater force?
The perpendicular distance from the pivot decreases, so a greater force is needed to produce the moment required at the crushing plate
Moving the hand towards the pivot increases the moment required at the crushing plate, so a greater force is needed at the handle
The perpendicular distance stays the same because the force is perpendicular to the handle, so a greater force is needed to increase the moment
The distance used to calculate the moment is measured from the crushing plate, so moving the hand towards the pivot requires a greater force
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.