Question

What is the electric potential at a point midway between two charges, -4.11 microC and -8.06 microC, separated by 21.94 cm?

Answer 1

The electric potential of a point charge is given by:

$V=k\frac{q}{r}$

where q is the charge and r is the distance between the charge and the point of interest. In this case we have two charges, then to calculate the total potential on a point we need to add the individual potential of each charge.

For both charges the point of interest is at 0.1097 m, then we have:

$\begin{gathered} V=(9\times10^9)(\frac{-4.11\times10^{-6}}{0.1097})+(9\times10^9)(\frac{-8.06\times10^{-6}}{0.1097}) \\ V=-0.997\times10^6 \end{gathered}$

Therefore, the electric potential midway of the charges is:

$V=-0.997\times10^6\text{ V}$