question_answer 41)

                  The centre of mass of an extended body on die surface of the earth and its centre of gravity                 (a) are always at the same point for any size of die body.                 (b) are always at die same point only for spherical bodies.                 (c) can never be at the same point.                 (d) is close to each other for objects, say of size less than 100 m.                 (e) both can change if the object is taken deep inside the earth.

Answer:

                  (d) Centre of mass coincides with the centre of gravity of a body if the size of the body is negligible as compared to the size (or radius) the earth.