Torque and Centre of Gravity
Torque is also known as moment of force or couple. When a force acts on a particle, the particle does not merely move in the direction of the force but it also turns about some point. So, we can define the torque for a particle about a point as the vector product of position vector of the point where the force acts and with the force itself. In the given figure, balancing of a cardboard on the tip of a pencil is done. The point of support, G is the centre of gravity.
The centre of gravity and the centre of mass of a body coincide, when
Options:
(a) `g` is negligible
(b) `g` is variable
(c) `g` is constant
(d) `g` is zero