Physics (AS & A Level) · Oct / Nov 2020 · Paper 11 · Question 12

Two people push a vertical gate to open it. The forces exerted by the people on the gate are shown. One person is distance d1 from the gate's hinge and pushes with horizontal force F1 at angle θ1 to the gate. The other person is at distance d2 from the hinge and pushes with horizontal force F2 at an angle θ2 to the gate. What is the total moment about the hinge due to forces F1 and F2?

1. A(d1 × F1 cos θ1) + (d2 × F2 cos θ2)
2. B(d1 × F1 sin θ1) + (d2 × F2 sin θ2)
3. C(d1 × F1 cos θ1) – (d2 × F2 cos θ2)
4. D(d1 × F1 sin θ1) – (d2 × F2 sin θ2)

As printed in the paper