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Homework Help: Rearrange equation

  1. Apr 17, 2010 #1
    1. The problem statement, all variables and given/known data

    F = A [Q][1][Q][2] / [r][2]

    Rearrange make A subject

    any one have any ideas?

    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Apr 18, 2010 #2

    tiny-tim

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    Welcome to PF!

    Hi missyfit! Welcome to PF! :smile:

    (try using the X2 and X2 tags just above the Reply box :wink:)

    Do you mean F = A Q1Q2 / r2 ?

    Just move the Qs and the r to the other side…

    what do you get? :smile:
     
  4. Apr 18, 2010 #3
    F = A Q1Q2 / r2 ?
    yes this is what was meant thanks

    by moving the Qs and r to other side is A the subject if it is left on the right?
     
  5. Apr 18, 2010 #4

    Redbelly98

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    Yes.
     
  6. Apr 18, 2010 #5

    tiny-tim

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    Or you can always swap the sides round, if it makes you happier. :smile:
     
  7. Apr 18, 2010 #6
    Thanks for both you inputs can you give an example of how you may work this out. do i need to do anything with the sqare root?

    missyfit
     
  8. Apr 18, 2010 #7

    tiny-tim

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    No, you show us what you think, and we'll comment. :smile:
     
  9. Apr 18, 2010 #8
    first i thought that swaping side over then wasnt sure what i should do with square root

    F = A Q1Q 2 / r2
    A Q1Q2 / r2 = F
    A Q1Q2 / r2 x Q1Q2 / r2 = F Q1Q2 / r2 x Q1Q2 / r2
    A = F Q1Q2 / r2

    this all seems abit bulky.
     
  10. Apr 19, 2010 #9

    tiny-tim

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    Hi missyfit! :smile:

    (just got up :zzz: …)
    uhh? whatever are you doing? :confused:

    start again. :smile:
     
  11. Apr 19, 2010 #10
    I guess i made a mess of this just learning equations and already finding it stressful. Dont worry thanks for help any way was following system we have been given to do equation clearly not very effective. :uhh:
     
  12. Apr 20, 2010 #11

    tiny-tim

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    Hi missyfit! :smile:

    (just got up :zzz: …)
    Sorry about the stress. :redface:

    Start by multiplying both sides of the original equation by r2

    what do you get? :smile:
     
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