[[Force and Translational Dynamics]]

Each force has an equal and opposite reaction.

If I push a wall with 50N's, it'll push back with 50N's, called an action reaction pair.
In formula format it's $F_{AB}=-F_{BA}$. The negative sign shows the forces point in opposite directions.
This also means that if 2 objects push off each other their COM doesn't change.
![[Pasted image 20260814131131.png]]

# Tension
Tension is a force applied by flexible connectors.

An ideal <small>yisang</small> string is one with **negligible mass and does not stretch**. In these ideal strings tension is equal throughout, in non ideals tension differs in different parts.