For a point mass the

**moment of inertia**is just the mass times the square of perpendicular distance to the**rotation**axis, I = mr^{2}. That point mass relationship becomes the basis for all other**moments of inertia**since any object can be built up from a collection of point masses.Correspondingly, what is the formula for rotational inertia?

**Rotational inertia**is a property of any object which can be rotated. It is a scalar value which tells us how difficult it is to change the

**rotational**velocity of the object around a given

**rotational**axis.

**Rotational inertia**plays a similar role in

**rotational**mechanics to mass in linear mechanics.

What is the rotary inertia?

**Rotational inertia**is the tendency of a

**rotating**object to remain

**rotating**unless a torque is applied to it.

Why moment of inertia is called rotational inertia?

**Moment of inertia**is the name given to

**rotational inertia**, the

**rotational**analog of mass for linear motion. It appears in the relationships for the dynamics of

**rotational**motion. The

**moment of inertia**must be specified with respect to a chosen axis of

**rotation**.