When object A exerts a force on object B, object B exerts an equal and opposite force on object A
Action-Reaction Pairs (Newton’s Third Law)
Motion observed from a specific frame of reference. The observed velocity depends on the observer’s perspective.
Relative Motion
A coordinate system from which motion is observed
Reference Frames
A force that opposes motion between surfaces.
Friction
An object in equilibrium has a net force of zero.
Applying Newton’s 1st Law (Equilibrium Analysis)
A visual representation of all forces acting on a single object.
Free-Body Diagrams (FBDs)