Question

why is momentum of inertia also called rotation inertia​

Answer 1

Answer. Moment of inertia is also called rotational inertia because it is a measure of the "resistence" of an object to be accelerated in its rotation. An object with a big moment of inertia is more difficult to increase/decrease its angular velocity (speed of rotation), than an object with a low moment of inertia.

Answer 2

Moment of inertia is also called rotational inertia because it is a measure of the "resistence" of an object to be accelerated in its rotation. An object with a big moment of inertia is more difficult to increase/decrease its angular velocity (speed of rotation), than an object with a low moment of inertia.