# Find the Electric Field

1. Feb 19, 2010

### Wildcatfan

1. The problem statement, all variables and given/known data
Consider two point charges placed on a line:

q1=1.00uc_______<2m>_________P_______<2m>________q2=-1.00uc

q1=1.00uc
q2=-1.00uc
r=2m

a) Find the electric field E at the position P *hint: bring + at P. Ep=Ep1+Ep2
b) Using the above E, find the electric force on the charge q=-1.00uc placed at P.

2. Relevant equations
(kq1/r12^2)

3. The attempt at a solution
I attempted to solve and with the charge acting on q1, I got 2.25X10^3 N/C. For the charge acting on q2, I received the answer -2.25X10^3 N/C. I figure this isn't correct since I need to use something other than 0 when these are added to figure out part b. Thanks for your help in advance!

2. Feb 19, 2010

### thebigstar25

:) you are right this is not zero ..

hint : remember that the electric field is a vector , and remember that the electric field produced from a positive charge is not the same as the negatice charge, check this figure:

http://img684.imageshack.us/img684/3059/38165338.jpg [Broken]

try to draw the electric field vector produced by both the positive and the negative charges , what will you get?

Last edited by a moderator: May 4, 2017