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Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीFor a system of particles, the internal forces cancel in pairs in the expression for net torque provided that:
Correct answer · Option 1
the internal forces satisfy Newton's third law and are directed along the line joining the interacting particles.
Explanation
The torque from action-reaction pairs vanishes if and only if the forces are equal, opposite, and act along the line joining the two particles (central forces), making \( (\mathbf{r}_i - \mathbf{r}_j) \times \mathbf{F}_{ij} = 0 \).
