Two particles of masses m1 and m2 are joined by a light rigid rod of length r. The system rotates at an angular speed ω about an axis through the centre of mass of the system and perpendicular to the rod. Show that the angular momentum of the system is L = μ r2 ω where μ is the reduced mass of the system defined as


The average momentum of the mass when at the middle of the system is denoted as


The average momentum is written as




And likewise, the angular momentum of mass is



Hence adding both the average momentum we get the net average momentum as



(The value of is denoted by )


Therefore, the net average momentum


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