Question

Three forces A, B and C are acting on a rigid body which can turn about O in fig.9. If all the three forces are applied simultaneously, in which direction will the body move? Explain.

Answer 1

The body will move in the direction of net torque

Net torque = sum of clockwise moments - sum of anticlockwise moments

In the given figure, force 40N is acting clockwise and forces 20N and 60N are acting anticlockwise 

Net torque = (40 x 3) - [(20 x 2) + (60 x 1)}

                   = 120 - 100 

                   = 20 Nm

Hence the body will move in clockwise direction about 'O'