Question

what is inertia at rest and inertia at motion?

Answer 1

First of all inertia is a tendency of a body to opose is change in position .
so when the the particals are in rest they oppose the change of there state this known as inertia of rest.

when particals are un motion the oppose the change in there state this is known as intertia of motion.

Answer 2

Here is the answer to your question!!

Inertia of rest :

Due to this inertia, the body at rest tends to remain at rest.

Inertia of Motion :

Due to this inertia, a body in uniform motion tends to continue it's motion

Hope it helped!!