# Gauss' Law: Infinite plane with charge

1. Oct 21, 2015

### SnakeDoc

1. The problem statement, all variables and given/known data
An infinite plane of charge has surface charge density 6.8 µC/m2. How far apart are the equipotential surfaces whose potentials differ by 100 V? In mm

2. Relevant equations
E=σ/(2ε0)

3. The attempt at a solution
So first I solved for E= 6.8e-6/(2*8.85e-12) = 384170.791

then because ΔV= E *ΔX
so
ΔX=ΔV/E

so then I substituted
ΔX = 100/ 384170.791
ΔX = .0002603

The site says that I've made a power of ten error the answer must be in mm but I'm not sure what Im doing wrong

2. Oct 21, 2015

### Staff: Mentor

So far you've expressed your ΔX in meters. What value did you enter for your answer in mm? How many significant figures did you provide?

3. Oct 21, 2015

### SnakeDoc

I entered 2.603 mm

4. Oct 21, 2015

### Staff: Mentor

Numerically the result looks to be good. How many significant figures do the given data support?

5. Oct 21, 2015

### SnakeDoc

I realized my mistake its supposed to be .2603mm I converted from Meters to millimeters improperly. Thank you.