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!

Homework Help: Coulombs law question

  1. Dec 2, 2013 #1
    1. The problem statement, all variables and given/known data

    This is the charge distribution:

    | 2.0 m
    2.0 m

    A = 2.0*10^-5 C
    B = -3.0*10^-5 C
    C = -3.0*10^-5 C

    a) Find the net force on the charge

    b) what is the net electric field acting on the charge

    2. Relevant equations


    electric field = Fnet/q

    3. The attempt at a solution

    a) The charges acting on A are equal and at equal distance so they are then same.



    F_E=1.35 N

    Each charge has a net force of 1.35 newtons on charge 1. However, force is a vector quantity so the vectors have to have the same direction in order to add them. (The forces are the same so we can simply multiply the hypotenuse of the electric force by 2 to find the net force on particle 1.



    Direction N45E

    (is this correct? my books solution to the problem involves adding x and y components which make a very confusion solution.)


    ε=190919 N/C
  2. jcsd
  3. Dec 2, 2013 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    That's not right. Is that what you meant to write?
  4. Dec 2, 2013 #3
    yes, i thought adding the vectors together at 45 degrees would be the same as adding x and y components and then using trigonometry to find the magnitude.
    Is it not equivalent?
  5. Dec 3, 2013 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes, if done correctly. Your answer was almost right, so I wondered if it was just a typo. If it's what you meant to post, please post your full working.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted