Newton's Three Laws of Motion

Steps

1. The First Law (Law of Inertia) states that an object at rest stays at rest, and an object in motion stays in motion at constant velocity, unless acted upon by an unbalanced force. This means objects naturally resist changes to their motion.
2. The Second Law states that force equals mass times acceleration (F = ma). This means the acceleration of an object depends on the net force acting on it and its mass—heavier objects need more force to accelerate at the same rate as lighter ones.
3. The Third Law states that for every action force, there is an equal and opposite reaction force. When you push on something, it pushes back on you with the same strength in the opposite direction.

Worked example

When you kick a soccer ball, the First Law explains why the ball was sitting still before you kicked it. The Second Law shows that the harder you kick (more force), the faster the ball accelerates, and a heavier ball would accelerate less with the same kick. The Third Law explains why your foot feels the impact—the ball pushes back on your foot with equal force as your foot pushes on the ball.

Remember

Newton's three laws work together to explain all motion: objects resist changes (inertia), force causes acceleration based on mass, and forces always come in equal and opposite pairs.