Newton's Laws of Motion: A Visual Guide for Students

Isaac Newton published his three laws of motion in 1687 and they still underpin every mechanics question on your Physics paper. Law one — inertia — states that an object stays at rest or in uniform motion unless acted upon by a net external force. The classic example: a passenger lurches forward when a bus brakes suddenly because their body wants to continue moving. Law two — F = ma — is the workhorse of calculations. Force equals mass times acceleration. If a 5 kg block accelerates at 3 m/s², the net force is 15 N. Always identify your system, draw a free-body diagram, and sum forces in each direction. Law three — action-reaction — states that for every force there is an equal and opposite reaction. A rocket expels gas downward (action); the gas pushes the rocket upward (reaction). Note that action-reaction pairs always act on different objects — they never cancel each other. Sketch these scenarios in your notes and link them to past-question contexts: projectile motion, inclined planes, and Atwood machines are the most common WAEC applications.