Assume that a stationary electron is a point of charge . What is the energy density u of its electric field at radial distances (a) r=1.00 mm, (b) r=1.00 `mu m` ( c) r=1.00 nm (d) r=1.00 pm, and (e ) r=1.00 fm (f) What is the u in the limit as `r to 0`?

Explanation

To solve the question regarding the energy density \( u \) of the electric field of a stationary electron at various radial distances, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Formula for Energy Density**:
The energy density \( u \) of an electric field is given by the formula:
\[
u = \frac{1}{2} \epsilon_0 E^2
...