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!

What is the net charge

  1. Jan 8, 2008 #1
    1. The problem statement, all variables and given/known data

    A metal sphere has a charge of +7.0 µC. What is the net charge after 8.00 10^13 electrons have been placed on it?
    in µC


    2. Relevant equations



    3. The attempt at a solution

    I believe that the charge of an electron is: -1.6 x 10^-19 C
    and there are 8 electrons,

    so -1.6 x 10^19 C * 8.00 x 10 ^13 electrons right?

    then I add it to 7 uC? well i'm having trouble with the sigfigs, I got 5.72 uC I don't believe that is correct.

    please help.
     
  2. jcsd
  3. Jan 8, 2008 #2
    Do you have a rounding error? I am getting -5.8µC.
     
  4. Jan 8, 2008 #3
    ah, I see from your answer. Sometimes it just takes someone else.

    it was my sign! it has to be negative.

    Thankyou!
     
  5. Jan 8, 2008 #4
    also, when i get the answer, after multiplying the electrons, does +7.0 uC have sigfigs? i can't seem to figure out why my calculater won't give me anything past 1.28 x 10^33 i believe.
     
  6. Jan 8, 2008 #5
    Sorry I don't understand your calculator comment. 7.0µC has 2 significant figures, and it means [itex]7.0*10^{-6}[/itex]C. 7.00µC would be 3 sig figs, and 7µC would be 1 sig fig.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: What is the net charge
  1. What is the net charge (Replies: 8)

  2. Net Charge (Replies: 12)

Loading...