Newton’s Laws of Motion

Newton’s three laws of motion, formulated by Sir Isaac Newton in the late 17th century, form the foundation of classical mechanics, describing how objects move under the influence of forces.

First Law: Inertia

An object at rest stays at rest, and an object in motion stays in motion with constant velocity, unless acted upon by a net external force. This is the concept of inertia.

Example: A book on a table remains stationary unless pushed.

Second Law: F = ma

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. Mathematically:

Where \(F\) is force (in Newtons), \(m\) is mass (in kg), and \(a\) is acceleration (in m/s²).

Example: Pushing a 2 kg box with 10 N of force:

Third Law: Action-Reaction

For every action, there is an equal and opposite reaction. Forces always come in pairs.

Example: When you jump, you push the ground down, and the ground pushes you up with equal force.

Applications

Newton’s laws are used in engineering (e.g., designing cars), astronomy (e.g., planetary motion), and everyday physics (e.g., sports dynamics).