Newton’s 3rd law
When exerting a force on something, that something always exerts an equal but opposite force on you. Typically called an action/reaction force-pair.
$$\vec F_\text{A on B}=-\vec F_\text{B on A}$$
When exerting a force on something, that something always exerts an equal but opposite force on you. Typically called an action/reaction force-pair.
$$\vec F_\text{A on B}=-\vec F_\text{B on A}$$
