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# UnitAcceleration

A unit of measure for acceleration.

```
class UnitAcceleration
```

## Overview

You typically use instances of [`UnitAcceleration`](/documentation/Foundation/UnitAcceleration) to represent specific quantities of acceleration using the [`NSMeasurement`](/documentation/Foundation/NSMeasurement) class.

### Acceleration

Acceleration is the rate of change of velocity. Acceleration can be expressed by SI derived units in terms of meters per second squared (m/s2).

The [`UnitAcceleration`](/documentation/Foundation/UnitAcceleration) class defines its [`baseUnit()`](/documentation/Foundation/Dimension/baseUnit()) as [`metersPerSecondSquared`](/documentation/Foundation/UnitAcceleration/metersPerSecondSquared), and provides the following units, which are initialized using [`UnitConverterLinear`](/documentation/Foundation/UnitConverterLinear) converters with the specified coefficients:

|Name                     |Method                                                                                         |Symbol|Coefficient|
|-------------------------|-----------------------------------------------------------------------------------------------|------|-----------|
|Meters Per Second Squared|``doc://com.apple.foundation/documentation/Foundation/UnitAcceleration/metersPerSecondSquared``|m/s²  |`1.0`      |
|Gravity                  |``doc://com.apple.foundation/documentation/Foundation/UnitAcceleration/gravity``               |g     |`9.81`     |

## Topics

### Accessing the Base Unit

[`baseUnit()`](/documentation/Foundation/Dimension/baseUnit())

Returns the base unit.

### Accessing Predefined Units

[`metersPerSecondSquared`](/documentation/Foundation/UnitAcceleration/metersPerSecondSquared)

Returns the meter per second squared unit of acceleration.

[`gravity`](/documentation/Foundation/UnitAcceleration/gravity)

Returns the gravity unit of acceleration.


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