AP Physics C: Electricity and Magnetism / Unit 8: Electric Charges, Fields, and Gauss's Law
8.3 Electric Fields
Notes
$\displaystyle \vec E=\frac{\vec F}{q_0}$. A point charge: $\displaystyle E=\frac{kq}{r^2}$. Fields from multiple charges add as vectors.
Practice
The field 2 m from a 4 μC charge ($k=9\times10^9$):
$\displaystyle \frac{9\times10^9\cdot4\times10^{-6}}{4}$.
An electron placed in a field feels a force:
Negative charge.
At the midpoint between $+q$ and $-q$, the field:
Both fields point the same way.
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