# mass

> Mass of the Rigidbody.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine](/engine/6000.7/script-reference/unityengine.md)
* **Assembly:** UnityEngine.Physics2DModule

```csharp
public float mass { get; set; }
```

### Remarks

The mass is given in arbitrary units, but the basic physical principles of mass apply. Newton's classic equation `force = mass x acceleration`, demonstrates that the larger an object's mass, the more force it requires to accelerate it to a given velocity. Mass also affects momentum, which is significant during collisions; an object with large mass will be moved less by a collision than an object with lower mass.

The mass can also be automatically calculated when [\_useAutoMass](/engine/6000.7/script-reference/unityengine/rigidbody2d/useautomass.md) is true. In this case, you cannot set the mass property directly.

Additional Resources: [\_useAutoMass](/engine/6000.7/script-reference/unityengine/rigidbody2d/useautomass.md)