Difference Between Momentum and Inertia

The concept of inertia and momentum are regularly confused because of their similar definitions. Inertia is the resistance offered by a body to the motion whereas momentum is the tendency of a body to continue moving. Let us look at the differences between the two to understand the concept better.

Difference between Momentum and Inertia

Momentum Inertia

Momentum is a vector quantity as it the tendency of a body to remain in motion.

Inertia is a scalar quantity as it is the resistance offered by the body to motion.

Momentum is denoted as ‘p’.

Inertia is denoted as ‘I’.

The momentum of a body of mass ‘m’ moving with a velocity of ‘v’ is calculated as p=m×v

The inertia cannot be calculated using a formula.

Linear momentum and angular momentum are the two types of momentum.

Inertia of rest, inertia of motion and inertia of direction are the three types of inertia.

Momentum depends on mass and velocity.

Inertia depends only on mass.

The total momentum is conserved.

Inertia has nothing to do with the conservation of energy.

The difference between between momentum and inertia should be understood clearly as these are an important topic in Physics. To Know more about momentum and inertia, Visit BYJU’S.

Practise This Question

A ball of radius R carries a positive charge whose volume density depends only on a separation r from the ball’s centre as ρ=ρ0(1rR), where ρ0 is a constant. Assuming the permittivities of the ball and the environment to be equal to unity, find the ratio of the magnitude of the electric field strength inside the sphere to that of the outside.