From 58b64b7176f6fa1dca8c5d15e6f169d9f0ca6138 Mon Sep 17 00:00:00 2001 From: arc Date: Tue, 6 Jan 2026 08:12:37 -0700 Subject: [PATCH] vault backup: 2026-01-06 08:12:37 --- education/physics/PHYS2220/Electric Charge.md | 3 +++ 1 file changed, 3 insertions(+) diff --git a/education/physics/PHYS2220/Electric Charge.md b/education/physics/PHYS2220/Electric Charge.md index a6204c4..27464fe 100644 --- a/education/physics/PHYS2220/Electric Charge.md +++ b/education/physics/PHYS2220/Electric Charge.md @@ -30,3 +30,6 @@ An electric dipole consists of two point charges of equal magnitude but opposite - The dipole field at large distances decreases as the inverse *cube* of the distance. This is because the dipole has zero *net* charge. # Continuous Charge Distributions +It's largely impossible to sum the electric field from every particle in a piece of matter, so the approximation is made that the charge is spread continuously over the distribution. +- If the charge distribution extends throughout a 3d volume, we describe it in terms of the **volume charge density** $\rho$, with units of $\frac{C}{m^3}$. +- For charge distributions spread over surf \ No newline at end of file