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# ForceMode.force

A constant force or torque applied to a body, influencing motion over time.

```
case force
```

## Discussion

The quantity that user sets via [`setForce(_:index:)`](/documentation/RealityKit/ForceEffectParameters/setForce(_:index:))
has the units of mass * distance /  time^2. i.e. a force ( mass * acceleration ).
`force` mode causes a change in acceleration that varies proportionally to a body’s mass.

The quantity that user sets via [`setTorque(_:index:)`](/documentation/RealityKit/ForceEffectParameters/setTorque(_:index:))
has the units of mass * distance^2 / time^2.
`force` mode causes a change in angular acceleration that varies proportionally to a body’s mass and inertia.

---

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