Question

Two bankrobbers are standing side by side, trying to push open the door of a safe which is 1.2 m wide. Each crook pushes with a force of 300 N, one at the center of the door, the other at the handle (far edge from the hinges). The total torque they exert is

(A) 180 N-m (B) 270 N-m (C) 360 N-m

(D) 540 N-m (E) 600 N-m

Answer 1

We know that torque about any point is given as:

Torque = Force × (perpendicular distance)

So, torque about point O is given as:

Torque = F×(L/2) + F × (L)

Torque = 300 N × (1.2/2 m) + 300 N×( 1.2 m)

Torque = 300 × (0.6) + 300 × (1.2) N-m

Torque = 540 N-m

Ans: D