A ring of diameter 0.4 m and mass 10 kg rotates about its symmetry axis at 1200 rpm. Find angular momentum (kg·m²/s).
Physics · Mixed Chapter
JEE Main Practice

Question

A ring of diameter 0.4 m and mass 10 kg rotates about its symmetry axis at 1200 rpm. Find angular momentum (kg·m²/s).

G1 Physics · Accepted Answer

Step 1: Radius r = 0.2 m, so ring inertia I = mr² = 10×(0.2)² = 0.4 kg·m². Step 2: Angular speed ω = (1200/60)×2π = 40π rad/s. Step 3: Angular momentum L = Iω = 0.4×40π = 16π ≈ 50.24 kg·m²/s.