How centre of gravity cancels all torques due to mg on a body?

Asked by dkp_ankit | 12th Dec, 2015, 03:36: PM

Expert Answer:

The torque acting on the centre of gravity will be
 
begin mathsize 14px style straight tau subscript straight C. straight M end subscript equals straight r subscript straight C. straight M end subscript cross times straight F equals straight r subscript straight C. straight M end subscript cross times mg end style
 
Now, the distance of centre of mass with itself will be zero.
Therefore, the torque due to mg on a body is zero. However, the torque on other points on the body will not be zero.
Hence, we can say that the centre of gravity cancels all the torques due to weight (mg) on a body.

Answered by Romal Bhansali | 14th Dec, 2015, 11:40: AM