# Homework Help: Electric feild sketch

1. Feb 19, 2010

### cerium

1. The problem statement, all variables and given/known data
Sketch 2 diagrams 1 showing Ex against x and 1 showing Fx against x

2. Relevant equations

3. The attempt at a solution
I have drawn a graph showing potential difference against x and have been asked to produce a sketch showing Ex and Fx relating to this graph but Im unsure how to do this, will my sketch of Ex be going from positive to negative if my pd went from neagative to positive

2. Feb 19, 2010

### gabbagabbahey

What is the equation that determines the electric field from its potential? What does that equation reduce to when the potential depends only on $x$?

3. Feb 19, 2010

### cerium

Equation relating electric field and potential is Ex= -dV(r)
dx
if it just relies on x then is it just an inverse sketch of the pd graph