1. Calculate the Divergence: Find $\nabla \cdot \mathbf{F}$ first.
2. Evaluate the Volume: Find the volume of the closed surface ($E$).
3. Multiply: If Divergence is constant, $\text{Flux} = \text{div } \mathbf{F} \times \text{Volume}$.
4. Integrate: If Divergence is not constant, solve $\iiint \text{div } \mathbf{F} dV$.
Find the outward flux of $\mathbf{F} = \langle 2x, 3y, z \rangle$ across a cube defined by $0 \le x, y, z \le 1$.
Step 1: Find the divergence $\nabla \cdot \mathbf{F}$.
Step 2: Use the Divergence Theorem to find the Total Flux.
If you have a vector field with **Zero** divergence ($\\nabla \cdot \mathbf{F} = 0$), what is the total flux across ANY closed surface? Does it matter if the surface is a cube or a sphere? Explain what this tells you about a "Pure Conduit" life.
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Find the flux of $\mathbf{F} = \langle x, y, z \rangle$ across a sphere of radius $R = 2$.
Note: Volume of a sphere $= \frac{4}{3}\pi R^3$.
The Calculation:
1. Find divergence.
2. Calculate Volume.
3. Multiply.
If $\text{div } \mathbf{F} = -5$ everywhere inside a vessel of volume 10... what is the total flux through the skin of the vessel?
The Spirit field inside a room is $\mathbf{F} = \langle x^2, y^2, z^2 \rangle$.
The room is a box: $0 \le x \le 2, 0 \le y \le 2, 0 \le z \le 2$.
Task: Find the total outward flux of the Spirit through the walls.
Objective: Explain the Divergence Theorem to a younger student using a colander and water.
The Activity:
1. Put your hands inside the colander.
2. Turn on the faucet above your hands.
3. "The water leaving the holes is exactly the same as the water hitting my hands."
The Lesson: "Our life is like this colander. What God puts in our heart is exactly what the world sees coming out of our skin."
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