A thin circular ring of mass M and radius R rotates at angular speed ω. Two small particles each mass m are gently fixed at opposite ends of a diameter. Find final angular speed.
Options

Question

A thin circular ring of mass M and radius R rotates at angular speed ω. Two small particles each mass m are gently fixed at opposite ends of a diameter. Find final angular speed.

G1 Physics · Accepted Answer

Step 1: Angular momentum is conserved: initial I=M R². Step 2: Added masses contribute 2mR², so (MR²)ω=(M+2m)R²ωf. Step 3: Therefore ωf=Mω/(M+2m). Final answer: B — Mω/(M+2m).