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Q6.7: NCERT Physics - Part 1 SYSTEMS OF PARTICLES AND ROTATIONAL MOTION 6.7 Solution: Two particles, each of mass m and speed v, travel in opposite…
⚠️ Common Exam Traps & Conceptual Pitfalls
Students often assume angular momentum is always origin-dependent and fail to recognize that when the total linear momentum of a system is zero ($\vec{P}_{total} = 0$), the angular momentum becomes invariant with respect to the choice of reference point.
Two particles, each of mass m and speed v, travel in opposite directions along parallel lines separated by a distance d. Show that the angular momentum vector of the two particle system is the same whatever be the point about which the angular momentum is taken.
Step-by-Step Verified Solution
**Answer:** (clockwise), independent of reference point.
**Step-by-Step Explanation:**
The total linear momentum of the system is zero. Therefore, the angular momentum about any point is the same as the angular momentum about the centre of mass. About the CM, the angular momentum is (clockwise). Since the net momentum is zero, is independent of the choice of origin [citation:6].
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