# Help find work done associated with electric potential

1. Dec 4, 2007

### trustabdy

given that the electric potential is .70 V higher outside the cell than inside the cell, and that the cell memberane is .1X10^-6 thick. calculate that work that must be done (in joules) to move one sodium ion from inside the cell to outside

i know V= .70V distance is .1X10^-6
i made the inside the cell potential energy is 0

????

2. Dec 4, 2007

### Staff: Mentor

What's the definition of potential difference?

3. Dec 4, 2007

### trustabdy

W = Fd = qEd

E=Volts/distance

how do i find the charge (q)

4. Dec 4, 2007

### trustabdy

amount of energy that would be required to move an object from one place to another against various types of forces.

ok

5. Dec 4, 2007

### Staff: Mentor

Combine these two equations.

What's the charge on a sodium ion? (What's an ion?)

6. Dec 4, 2007

### trustabdy

is it one electron since sodium is in the first column in the periodic table

7. Dec 4, 2007

### Staff: Mentor

The charge on the sodium ion is +e, since it is missing an electron. (That's what makes it an ion.)

8. Dec 4, 2007

### trustabdy

W = Fd = qEd
q= charge on electron
d= distance
E= Volts/distance
am i right?

9. Dec 4, 2007

### Staff: Mentor

Combine this:
With this:
To get a simpler equation.

10. Dec 4, 2007

### trustabdy

so this W=qEd is the correct equation to find work done in joules. or are there any other equations