# Inertia

Ideal mechanical rotational inertia

## Library

Mechanical Rotational Elements

## Description

The Inertia block represents an ideal mechanical rotational inertia, described with the following equation:

`$T=J\frac{d\omega }{dt}$`

where

 `T` Inertia torque `J` Inertia ω Angular velocity `t` Time

The block has one mechanical rotational conserving port. The block positive direction is from its port to the reference point. This means that the inertia torque is positive if inertia is accelerated in positive direction.

## Dialog Box and Parameters

### Parameters Tab

Inertia

Inertia. The default value is `0.001` kg*m^2.

### Variables Tab

Use the Variables tab in the block dialog box (or the Variables section in the block Property Inspector) to set the priority and initial target values for the block variables prior to simulation. For more information, see Set Priority and Initial Target for Block Variables.

## Ports

The block has one mechanical rotational conserving port, associated with the inertia connection to the system.