Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीConsider the following statements regarding the centre of mass (CM) and centre of gravity (CG) of an extended body: (A) The centre of mass of a body depends on the distribution of its mass and is independent of the gravitational field. (B) The centre of gravity of a body coincides with its centre of mass only if the gravitational field is uniform across all parts of the body. (C) In an extended non-uniform gravitational field, the net gravitational torque on the body about its centre of mass is necessarily zero. (D) The total torque on a system is independent of the choice of origin if the net external force on the system is zero. Choose the correct answer from the options given below:
Correct answer · Option 1
(A), (B) and (D) only
Explanation
Statements (A), (B), and (D) are standard principles from the text. Statement (C) is false because in a non-uniform gravitational field, the gravitational torque about the CM is non-zero (it vanishes about the CG, not CM).