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## Homework Statement

A small object with a mass of 350mg carries a charge of 30nC and is suspended by a thread between the vertical plates of a parallel-plate capacitor. The plates are separacted by 4 cm. If the thread makes an angle of 15 degrees with the vertical, what is the potential difference between the plates?

## The Attempt at a Solution

First, I drew a diagram. Since the object has a + charge, it would be more closer to the negative plate.

[tex]\Delta V=\frac{U_{E}}{q}[/tex]

[tex]U_{E}=qEd[/tex] , [tex]E=\frac{kq}{r^2}[/tex]

Now that I have all the required info to solve for the electrical potential energy, I solved it and put it into the equation: [tex]\Delta V=\frac{U_{E}}{q}[/tex]

For the electrical potential energy I got: 2.023*10^-4J

For the answer (the potential difference) I got: 6742.5V

Does my method seem correct? This is an even problem so I have no way of checking my answer for accuracy. Thanks in adv.