- 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 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:
$$ $\vec(F)_B = q\vec(v) \times \vec{B} $$