A circular stage platform can rotate about an axle through its centre. Three people apply forces to the platform. The table gives the perpendicular distance from the axle to each force's line of action.
| Force | Size of force | Perpendicular distance from the axle to the force's line of action | Direction of moment |
|---|---|---|---|
| A | 140 N | 0.75 m | clockwise |
| B | 65 N | 0.60 m | anticlockwise |
| C | 30 N | 0.80 m | anticlockwise |
A fourth person applies a force to the platform. The perpendicular distance from the axle to this force's line of action is 1.40 m. This force balances the platform.
Calculate the size of the force applied by the fourth person.
State whether this force produces a clockwise or an anticlockwise 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.