# Potential homework problem help

1. Feb 6, 2010

### gwenle1

1. If the Earth had a net surface charge density of 1.0 electron per square meter a) what would be the total charge on the earth's surface? b) what would be the electric potential and c) what would be the electric field, just outside the earth's surface?

Attempt: I tried using charge of electron (-1.6 x 10^-19C/m^2) and rearranging equations of electrostatics but cannot come up with the answer.

The solutions should be -82microC, -0.12V and 18nV/m

2. Feb 6, 2010

### fluidistic

Re: Potential

Welcome to PF!
It would be nice if we could see your attempt.
Start with a). The Earth has a surface charge density of 1 electron/m². How many m² does the Earth have? Thus, how many free electrons?

3. Feb 6, 2010

### gwenle1

Re: Potential

ok. Thanks for that clarification. I got part A of the question.

4. Feb 6, 2010

### gwenle1

Re: Potential

The rest came easily thereafter too.
Easier than I thought- simple plug in and solve!