Rotational Motion
Class 11 · Rotational Motion

Lever Balance (Torque)

Two masses on a beam — adjust weights and arms; see torque balance live.

Run simulation

Key Notes

01

Lever balances when net torque about pivot is zero: m₁ g d₁ = m₂ g d₂.

02

Mechanical advantage = effort arm / load arm. First-class lever has pivot in the middle.

03

Most stable when COM is just above the pivot.

Formulas

Balance

Torque balance about pivot.

Mechanical advantage

Force amplification.

Important Points

Crowbar, scissors, seesaw — all first-class levers.

Wheelbarrow is a second-class lever (load between effort and pivot).

Lever Balance (Torque) notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 11 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.