A beam calculator

You will write three small functions for the fields of a beam. Use $\varepsilon_0 = 8.85 \times 10^{-12}\ \text{C}^2/(\text{N m}^2)$ and $c = 3.00 \times 10^{8}$ m/s.

The idea. A point source of power $P$ has the intensity $P/4\pi r^2$ at distance $r$. The peak electric field follows from $I = \tfrac{1}{2}\varepsilon_0 cE_0^2$, and $E_0 = cB_0$.

Your tasks.

1. In intensity, return the intensity in W/m² of a point source of power power in W at a distance distance in m.
2. In peak_e, return the peak electric field in V/m for an intensity intensity in W/m².
3. In peak_b, return the peak magnetic field in T for a peak electric field e_peak in V/m.