A horizontal arm in a parcel-sorting machine is supported by a pivot. The weight of the arm is negligible. All the forces shown act vertically downwards.
| Component | Side of pivot | Force | Distance from pivot |
|---|---|---|---|
| loaded tray | left | 18 N | 0.40 m |
| guide assembly | left | 12 N | 0.15 m |
| actuator | right | 24 N | variable, with a maximum of 0.35 m |
Calculate the distance from the pivot at which the actuator force must act to balance the arm.
Explain whether the actuator can keep the arm in rotational equilibrium.
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.