Angular Momentum
Interactive simulation — adjust parameters and watch the visualization update in real time.
Live graphs
How it works
For rotation about a fixed axis through the center, with no net external torque, the angular momentum L = Iω stays constant. If you redistribute mass closer to the axis (smaller r), the moment of inertia I = 2mr² drops, so ω must increase to keep the same L — the classic figure-skater effect.
Key equations
L = I ω · I = 2 m r² (two equal point masses)
If L fixed: ω′ = L / I′ · K = L² / (2I)