A printing press can use either gear R or gear S to move its paper rollers. The force at the teeth of each gear acts perpendicular to its radius. For gear R, the force is 150 N and the radius is 0.080 m. For gear S, the force is 100 N and the radius is 0.120 m.
Why do gear R and gear S produce the same moment about their axles?
The decrease in force is balanced by the increase in radius because moment is found by adding them
For each gear, multiplying the force at the teeth by the radius gives the same value
Both forces act perpendicular to their radii, so they produce equal moments regardless of force and radius
The smaller force is balanced by the larger radius because moment is found by dividing radius by 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.