Physics (AS & A Level) · Oct / Nov 2018 · Paper 13 · Question 12

A flat metal disc has radius R. Forces of magnitude F are applied tangentially at the edge of the disc. The forces are in the plane of the disc. Which arrangement of forces produces only a torque of magnitude 2FR?

1. ATwo forces F applied tangentially at opposite edges, producing a couple.
2. BTwo forces F applied tangentially at adjacent edges.
3. CTwo forces 2F applied tangentially at opposite edges, producing a couple.
4. DTwo forces 2F applied tangentially at adjacent edges.

As printed in the paper