1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Constant Electric Field and Potential

  1. Jan 31, 2009 #1
    1. The problem statement, all variables and given/known data

    The figure below shows two points in an electric field. Point 1 is at (X1,Y1) = (3,4), and point 2 is at (X2,Y2) = (12,9). (The coordinates are given in meters.) The electric field is constant with a magnitude of 59.3 V/m, and is directed parallel to the +X-axis. The potential at point 1 is 1200.0 V.

    [​IMG]



    2. Relevant equations

    Vf-Vi = -Integral from i to f (E*ds)



    3. The attempt at a solution

    I set Vi=1200V
    E = 59.3 N/C
    and tried to solve for Vf

    I found the distance by making a triangle connecting the two points to be the sqrt(106) and the angle formed to be 29deg. I took the cos(29) and brought that out of the integral(Im not sure if thats right, but I saw my book take the cosine of the angle so I did too).

    Vf-1200 = -59.3*cos(29)*integral(from i to f) of (ds)

    I solved for Vf and got 1148 V, but thats wrong. Any suggestions
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Jan 31, 2009 #2

    gabbagabbahey

    User Avatar
    Homework Helper
    Gold Member

    Looks like you just plugged the numbers in wrong. I assume that you recognized [tex]\int_i^fds=\sqrt{106}[/tex]?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?