Question

Two physical quantities Defined by first law of motion

Answer 1

Two physical quantities Defined by first law of motion are inertia and force.

Newton's first law states that “if a body is at rest ,it remains in rest and if it is in uniform motion then it will continue its uniform motion untill an external force is applied on it”

It explained that every body has the tendency to oppose the change in its state of rest or state of uniform motion.

So according to Newton's first law - “Force is an external factor which can change the state of rest or state of uniform motion of an object”