Physics Quiz: Part 5

Force: A force is a push or pull that can cause an object with mass to accelerate. The key quantity is the Net Force ($Σ\vec{F}$), which is the vector sum of all forces acting on an object.

Newton's First Law (Inertia): An object remains at rest or in constant velocity motion unless a net force acts on it. If $Σ\vec{F} = 0$, then $a=0$.

Newton's Second Law: The cornerstone of dynamics. It relates net force, mass, and acceleration. $$Σ\vec{F} = m\vec{a}$$

Newton's Third Law (Action-Reaction): For every action, there is an equal and opposite reaction. Forces always come in pairs acting on different objects: $ \vec{F}_{AB} = -\vec{F}_{BA} $.

Common Forces: Gravity/Weight ($W=mg$), Normal Force ($N$), Tension ($T$), and Friction ($f$).