What Are Forces?

A force is a push or pull. Forces make things move, stop, or change direction. The study of how and why objects move is called mechanics.

Newton’s Laws of Motion

• First Law (Inertia): Things want to keep doing what they’re doing—moving objects keep moving, and stopped objects stay stopped—unless a force acts on them.
• Second Law: The bigger the force, the more something accelerates: \( F = ma \) (Force = mass × acceleration).
• Third Law: For every action, there’s an equal and opposite reaction.

Everyday Forces

• Gravity: Pulls you toward Earth.
• Friction: Slows things down when they rub together.
• Magnetism: Pulls or pushes objects without touching them.

Why Forces Matter

Forces explain why we walk, cars drive, and planes fly!