Question

1
(vil) The centre of mass of a system of particles
| (a) coincides always with the centre of gravity.
(b) never coincides with the centre of gravity.
(c) coincides with the centre of gravity only in a uniform
gravitational field.
​

Answer 1

Answer:

Centre of mass:

It is the point where whole mass of the body is concentrated. If an external force is applied on COM , it torque will be zero.

Centre of gravity:

It is the point where the torque of gravitational force is zero.

COM and CAG mag or mag not coincides

couple only produces rotation, no translation

Mechanical advantage =

Input force

output force

If it is grater than 1

Output > 1 input

So, less effort is required to lift large low