Divergence

Sources and sinks

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Divergence ∇ · F = ∂P/∂x + ∂Q/∂y: outflow per unit area.
• Positive divergence: a source; negative: a sink.
• Incompressible flow has zero divergence.

Steps

1. A tiny box
2. Compute a divergence
3. Neither source nor sink
4. Water in a pipe
5. An outflowing square
6. Electric charges