Newton’s Laws of Motion

Motion in Physics

Motion is one of the major topics in physics. It is a part of mechanics. Scientists have set different laws or rules which explain motion and the causes of changes in motion.

Mathematical Principles of Natural Philosophy

The most famous laws of motion were formulated by Sir Issac Newton. The three laws of motion were compiled by him in Mathematical Principles of Natural Philosophy (published in 1687) His laws of motion are three physical laws which actually laid the foundation for classical mechanics. Scientists have used certain basic terms to describe motion.

Terms used to describe motion

Force: It is required to act on an object to move it or to change its motion.
Velocity: It is also known as speed .Velocity of an object is influenced by forces.
Acceleration: It is a measure of how much the velocity of an object changes in a certain time (one second).
Mass: It is the amount of something present and is measured in grams or kilograms.

What are the three laws of motion?

1. Newton’s first law of motion

Every object in a state of motion tends to remain in that state of motion unless an external force is applied to it. This is also known as Law of inertia.

2. Newton’s second law of motion

The relationship between an object’s mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors. In this law the direction of the force vector is the same as the direction of the acceleration vector. This law defines how velocities change when forces are applied.

3. Newton’s third law of motion

For every action there is an equal and opposite reaction. This happens in a situation such as if we step off a boat onto the bank of a lake. As one move in the direction of the shore, the boat tends to move in the opposite direction. If not careful, the person may fall.

Laws of motion facts

The three laws of motion are verified over years by experiments and observations. They are found to be excellent approximations at the scales and speeds of everyday life. However, these are inappropriate for use at very small scales, very high speed and strong gravitational fields.