OnlineCBT
Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीGiven below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The acceleration of the centre of mass of a system of particles is determined exclusively by the external forces acting on the system. Reason (R): The internal forces between particles occur in equal and opposite pairs according to Newton's third law and sum to zero. In the light of the above statements, choose the correct answer from the options given below:
Correct answer · Option 1
Both (A) and (R) are true and (R) is the correct explanation of (A).
Explanation
Internal forces cancel in pairs by Newton's third law, so \( \sum \mathbf{F}_{\text{int}} = 0 \), leaving \( M\mathbf{A} = \mathbf{F}_{\text{ext}} \). Thus (R) correctly explains (A).
