The Second Law of Motion

The Second Law of Motion

When an object at rest begins to move, it has an acceleration since the velocity changes. In the same way, when an object changes its state of motion, it has an acceleration because the  velocity changes.

Whenever an unbalanced force acts on an object, it produces an acceleration on the object.

The second law of motion states that :

The unbalanced force acting on a particle is proportional to the acceleration it produces on the particle.

Fnet µ a

Fnet  = m a

m is a constant and is called the mass of the object.

Unit of Force

The second law of motion helps us to measure force using the relation :

Fnet = m a

m is the mass of the particle and it is measured in kilogram (kg).

Acceleration is measured in m/s².

There, force is measured in kg.m/s².

Kg.m/s² is called a Newton (N).

Unit of force is the Newton (N).

The amount of force that produces an acceleration of 1 m/s² on particle of mass 1 kg is called one newton.