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: Magnetic field of a moving charge

  1. Mar 2, 2016 #1
    1. The problem statement, all variables and given/known data
    A negative charge q = −3.20×10-6C is located at the origin and has velocity υ⃗ =(7.50×104m/s)ι^+((−4.90)×104m/s)j^.
    At this instant what is the magnetic field produced by this charge at the point x = 0.230 m , y = -0.300 m , z= 0? Give the x, y and x components

    2. Relevant equations
    B = u0/4π. (qv x r)/r2

    3. The attempt at a solution
    So to find Bx i've tried using r = 0.230 and v = 7.5x104 giving 10-7 x 3.2 x 10-6 x 7.5 x 104/0.2302. However i have a feeling I can't just take the x/y components individually. I know that a cross product goes to 1 if the components are perpendicular and 0 if they are parallel and feel like this will help but i just can't put it all together to give me the correct answer. any hints would be very much appreciated!
  2. jcsd
  3. Mar 3, 2016 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    You are correct - you cannot just take the components individually like that. You have a vector equation, why not use it?
    Do you know how to evaluate a cross product between two arbitrary vectors?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted