A horizontal mobile sculpture can rotate freely about a pivot. Two ornaments exert downward forces on opposite sides of the pivot. The weight of the supporting bar can be ignored.
| Ornament | Side of pivot | Force exerted | Perpendicular distance from pivot |
|---|---|---|---|
| P | left | 20 N | 0.45 m |
| Q | right | 30 N | ddd |
The mobile sculpture is initially balanced.
Calculate the distance ddd.
Ornament P is moved to a perpendicular distance of 0.30 m from the pivot. Ornament Q is not moved.
An additional downward force is applied at a perpendicular distance of 0.20 m to the left of the pivot.
Calculate the additional downward force needed to balance the mobile sculpture.
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.