Question

A roller with a diameter of 0.2 m is raised over a pavement AB by applying forces F₁ and F₂ as shown in the diagram.

If the magnitude of both forces is 20 N, then compare the magnitudes of the torques produced by the two forces.

Answer 1

The roller’s radius is 0.2 ÷ 2 = 0.1 m.

Since the forces are tangential, each has a perpendicular distance of 0.1 m from the roller’s centre.

Thus, the torque produced by each force is 20 × 0.1 = 2 N m.

Their torques are equal in magnitude, though they act in opposite directions.