diff --git a/education/physics/PHYS2220/Magnetism.md b/education/physics/PHYS2220/Magnetism.md
index ccc9eab..586576f 100644
--- a/education/physics/PHYS2220/Magnetism.md
+++ b/education/physics/PHYS2220/Magnetism.md
@@ -1,3 +1,6 @@
 - Magnetic fields are represented with the symbol $\vec{B}$
 - Magnetism is based in *electric charge*, specifically the motion of that charge.
-- The magnetic force is always at right angles to both the velocity $\vec{v}$, and the magnetic f
\ No newline at end of file
+- The magnetic force is always at right angles to both the velocity $\vec{v}$, and the magnetic field $\vec{B}$
+- The force is greatest when the charge is moving at right angles and is zero for motion parallel to the field. THe force is generally proportional to $\sin(\theta)$, where $\theta$ is the angle between the velocity $\vec{v}$, and the field $\vec{B}$.
+The formula that describes magnetic force compactly is:
+$$ $\vec(F)_B = q\vec(v) \times \vec{B} $$