# Sandbox.PhysicsGroup.ApplyImpulse

```csharp
void ApplyImpulse(Vector3 vel, bool withMass = False)
```

Adds given amount of linear impulse ([Sandbox.PhysicsBody.ApplyImpulse](/api/Sandbox.PhysicsBody/ApplyImpulse)) to all physics bodies in this group.

### Parameters

- `vel` (`Vector3`): Velocity to apply.
- `withMass` (`bool`), default `False`: Whether to multiply the velocity by mass of the [Sandbox.PhysicsBody](/api/Sandbox.PhysicsBody) on a per-body basis.

Declared in [Sandbox.PhysicsGroup](/api/Sandbox.PhysicsGroup).
Assembly: `Sandbox.Engine`.