# Mass

Ideal mechanical translational mass

## Library

Mechanical Translational Elements

## Description

The Mass block represents an ideal mechanical translational mass, described with the following equation:

`$F=m\frac{dv}{dt}$`

where

 `F` Inertia force `m` Mass `v` Velocity `t` Time

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

## Dialog Box and Parameters

### Parameters Tab

Mass

Mass. The default value is `1` kg.

### 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 translational conserving port, associated with the mass connection to the system.