ELI5: Explain Like I'm 5

Principle of moments

Principle of moments is a rule that tells us how to balance things by spreading out their weight or mass. Imagine if you had a seesaw – one side is heavier than the other. You would have to put something on the lighter side to make it balance. That something is an example of the principle of moments. It is an object resisting the weight or force of the heavier side.