Question

what is meant by momentum and inertia.

Answer 1

Momentum:- The quantity of motion of a moving body, measured as a product of its mass and velocity.

Inertia:- The resistance of any physical object to any change in its position and state of motion. 

Answer 2

✴Momentum=> A vector quantity that is the product of the mass and the velocity of an object or particle.

✴Inertia=> The physical force that keeps things where they are or keeps them moving in the direction they are travelling.