Question

The question I am answering is:
A 5.0 uC point charge is moved within an electric field and has an electric potential energy change of 10.0 J. What is the electrical potential difference before and after the charge was moved? (uC = 1.0 x 10^-6 C)

Answer 1

\[V = \frac{U}{Q}\]

by definition, voltage V is potential energy U per unit charge (or Coulumb) Q.

the question is badly worded but they want you to calculate the change in potential (commonly called potential difference) due to change in energy.

Answer 2

Okay, so where does the 1.0x10^-6 come into play?

Answer 3

they're telling you that \[1 \mu C = 10^{-6} C\]

Answer 4

So should I set this up as 2 different equations since I need the before and after values?

Answer 5

you don't need the before and after

they have given you: ""an electric potential energy change of 10.0 J""

they want: ""the electrical potential difference before and after the charge was moved"" but as i said that is badly worded and meaningless.

what they really want is the **potential difference** associated with that energy change, ie the **change in potential** associated with that energy change.

hope that makes sense.

Answer 6

I'm sorry for the trouble, I've just begun learning this, that makes plenty of sense! So would I go about setting it up as,
V = 10.0 J / (1.0x10^-6)(5)

Answer 7

no worries, that looks good, well done!

Answer 8

thanks for all the help!! Would you mind helping me out with another about angle of incidence and refraction?

Answer 9

sure, start a new thread and i can get back to you tomorrow, though you will probably find someone else answers before then.

@matt101 is great for all kinds of physics.

Answer 10

Hey thanks for the shout out @IrishBoy123!

And @eturpin1 sure feel free to tag me in any posts you need a hand with and I'll have a look!