Question

what is formula of inertia?

Answer 1

Inertia is the resistance an object has to a change in its state of motion. This varies with mass and an object's mass is solely dependent upon the inertia of an object. The more inertia an object has, the more mass it has...there's no special formula for inertia in a linear sense.

http://www.physicsclassroom.com/class/newtlaws/u2l1b.cfm

However, you can calculate the *moment* of inertia in rotational motion:
http://hyperphysics.phy-astr.gsu.edu/hbase/mi.html
http://hyperphysics.phy-astr.gsu.edu/hbase/mi2.html

Answer 2

thanks