Lever and Torque: Rotational Equilibrium

Theory

A body is in rotational equilibrium when the net torque is zero: $\sum \tau =\sum Fd=0$. For a lever (Archimedes’ law of the lever): $m_{1}g{d}_1=m_{2}g{d}_2$.

What to observe

• Left: 2 kg at 2 m balances 4 kg at 1 m.
• Right: 2 kg at 2 m against 2 kg at 1 m — the beam tips over.

Try this

• Drag a weight along the beam during the simulation.
• Change a mass in the properties panel and find the new balance point.

Also available in: Alavanca e torque: equilíbrio de rotação (Português) · Palanca y torque: equilibrio de rotación (Español)