1. Limited time only! Sign up for a free 30min personal 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!

Electric Force

  1. Jan 25, 2012 #1
    1. The problem statement, all variables and given/known data

    1. Charge q1= 1.00*10^-9C is located +0.01 m from the origin along the x-axis. Charge q2= 2.00*10^-9C is located +0.03 m from the origin. What is the electric force exerted by these two charges on a third charge, q3= 1.5*10^-9C, located at the origin?

    a. 1.65*10^-4N

    *b. 1.4*10^-4N

    c. 4.4*10^-4N

    d. 6.1*10^-4N

    2. Relevant equations

    F=kq1q2/r^2
    Ftotal=F1+F2...Fn

    3. The attempt at a solution

    both charges q1 and q2 exert a repelling force in the same direction with different magnitudes on charge q3

    Ftotal=Fq1+Fq2
    Ftotal=kq1q3/r1-32+kq2q3/r2-32
    Ftotal=kq3((q1/r1-32)+(q2/r2-32))
    Ftotal=9x109*1.5x10-9(1.0x10-9/(.01)2)+(2.0x10-9/(.03)2))
    Ftotal=1.65x10^-4

    the answer key says it is supposed to be B but I get A...what am I doing wrong?
     
  2. jcsd
  3. Jan 25, 2012 #2

    gneill

    User Avatar

    Staff: Mentor

    Are you sure that all three charges are located along the x-axis?
     
  4. Jan 25, 2012 #3
    It doesnt specify, so I assumed since the first one is along the x axis the second one is two.
     
  5. Jan 25, 2012 #4

    gneill

    User Avatar

    Staff: Mentor

    Suppose, just for the sake of curiosity, that the second charge was located at y = +0.03m on the y-axis. What would the net force magnitude be on q3 at the origin?
     
  6. Jan 25, 2012 #5
    1.38x10^-4 so it was supposed to say it was at the y axis
     
  7. Jan 25, 2012 #6

    gneill

    User Avatar

    Staff: Mentor

    That would be my guess, yes.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Electric Force
  1. Electric Force (Replies: 3)

  2. Electric Forces (Replies: 5)

  3. Electric Forces (Replies: 3)

  4. Electric force (Replies: 5)

  5. Electric Force (Replies: 13)

Loading...