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Help needed with rearranging an equation

  1. Nov 20, 2011 #1
    Im having trouble rearranging an equation to find a value for I.



    [The given equation is mgh = 1/2*Iw^2 + 1/2*mv^2 + Tf * theta


    My attempt was a bit of a stab in the dark as i am useless with rearranging equations.

    I = mgh/w^2 + 1/2*mv^2 + Tf * theta


    Many thanks
     
  2. jcsd
  3. Nov 20, 2011 #2
    To make I subject of the equation is like peeling an onion.

    First step: Transfer those two terms on the RHS not involving I to the LHS.
     
  4. Nov 20, 2011 #3
    ok so you end up with

    mgh - 1/2*mv^2 - Tf*theta = 1/2*Iw^2

    Would the lhs be divided by 1/2 w^2?

    Thanks
     
    Last edited: Nov 20, 2011
  5. Nov 20, 2011 #4
    Yes we 'peel the next layer of the onion' by dividing BOTH sides by [itex]\frac{\omega^{2}}{2}[/itex] to isolate the I by itself on the RHS.
     
  6. Nov 23, 2011 #5
    Nice one cheers
     
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