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: Need help with an Electric Field Question

  1. Nov 12, 2015 #1
    I need help with what seems to be a simple Electric filed question. I want to mak3 sure that the explanation (attempt at a solution) is sound and make sense. Thanks!

    1. The problem statement, all variables and given/known data

    If an electric field of magnitude 150,000 N/C points due north at a certain spot, what is the magnitude and direction of the force that acts on a charge of -12 uC?

    2. Relevant equations
    E = F / q0

    3. The attempt at a solution

    Correct answer: 1.8 N to the south

    First, we need to determine the magnitude of the force acting on the charge. Multiply the magnitude of the electric field (E) by the magnitude of the test charge (q0). Because the charge is negative, it acts opposite to the direction of the electric field.

    E = F / q0
    Convert to solve for F:
    F = Eq0
    F = (150,000 N/C) × (-12 uC) -- [remember that 1 uC is 1 × 10^-6 C]
    F = (150,000 N/C) × (-0.000012)
    F = -1.8 N
    The negative sign in the answer indicates the direction of the force of the field.
    F = 1.8 N to the south.
  2. jcsd
  3. Nov 12, 2015 #2


    User Avatar
    Science Advisor
    Homework Helper
    2017 Award

    Hello Ken, :welcome: !

    True enough. Good posting. There's no question ?

    [edit] Ah, you want a stamp "Approved by PF!"

    Unfortunately, those stamps don't exist (they wouldn't really have any value: teachers are almost above the law).
    But if they would exist, you sure would be the first in line to get your work stamped thay way :smile:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted