Halliday, Resnick & Walker — Electric Potential: Problem 51

51 The ammonia molecule $NH_3$ has a permanent electric dipole moment equal to $1.47\text{ D}$, where $1\text{ D} = 1\text{ debye unit} = 3.34 \times 10^{-30}\text{ C}\cdot\text{m}$. Calculate the electric potential due to an ammonia molecule at a point $103\text{ nm}$ away along the axis of the dipole. (Set $V = 0$ at infinity.)