Question
What is the internal energy of a system consisting of two point charges, one 2.0 μC, and the other −3.0 μC, placed 1.2 m away from each other?
1. $-3.8 \times 10^{-2} \textrm{ J}$
2. $-4.5 \times 10^{-2} \textrm{ J}$
3. $4.5 \times 10^{-2} \textrm{ J}$
4. $3.8 \times 10^{-2} \textrm{ J}$

(b)

Solution Video