Principle of Moments Demo | Interactive Torque Animation

Principle of Moments

Understanding Torque and Equilibrium

The Principle of Moments, also known as Varignon's Theorem, states that for a system to be in rotational equilibrium, the sum of clockwise moments about any point must equal the sum of anticlockwise moments about that same point.

Σ (Clockwise Moments) = Σ (Anticlockwise Moments)

Where moment (or torque) is calculated as: Force × Perpendicular distance from the pivot.

5N

5N

Weight 1

Weight 2

2m

2m

Key Observations:

• When moments are balanced, the system is in rotational equilibrium and remains stationary.
• When moments are unbalanced, the system rotates about the pivot point.
• Balance can be achieved by either adjusting the weights or their distances from the pivot.
• The principle applies to all rotational systems, from simple levers to complex machinery.

Interactive Demonstration of the Principle of Moments | TThe Physics Next