Newton's three laws of motion, formulated by Sir Isaac Newton in 1687, are fundamental principles of classical mechanics that describe the relationship between an object's motion and the forces acting upon it. These laws define inertia (objects stay put or move straight),Β
Β (acceleration depends on mass/force), and action-reaction pairs.
Newton's First Law (Law of Inertia): An object at rest stays at rest, and an object in motion stays in motion with a constant velocity unless acted upon by an unbalanced external force. For example, a soccer ball sits still until kicked, and a passenger moves forward when a car brakes suddenly.
Newton's Second Law (
F=macap F equals m a
πΉ=ππ): The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (
Force=MassΓAcceleration Force equals cap M a s s cross cap Acceleration
πΉππππ=πππ π Γπ΄ππππππππ‘πππ). A heavier object requires more force to accelerate than a lighter object.
Newton's Third Law (Action-Reaction): For every action, there is an equal and opposite reaction. If one object exerts a force on a second object, the second object exerts a force of equal magnitude in the opposite direction on the first. Examples include a rocket launching by expelling gas downward to push itself upward, or pushing against a wall.Β