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Homework Help: Capacitance using an axon ?

  1. May 4, 2010 #1
    Capacitance using an axon.. :)?

    1. The problem statement, all variables and given/known data
    An axon membrane is 8.0×10-9 m thick.
    a) Find the dielectric constant of the membrane, if the capacitance C is 100 nF for an area A = 10.0 square mm.
    b) If the resting potential across the membrane is ΔV = - 90 mV, what is the charge ±Q on each surface A?
    c) For this area of membrane at -90 mV, what is the stored electric energy?



    2. Relevant equations
    C=k(eoA)/D


    3. The attempt at a solution
    Basically plugging in the values however i do not know what eo is and the value of it.




    Thank you for your help.
     
  2. jcsd
  3. May 4, 2010 #2
    Re: Capacitance using an axon.. :)?

    Okay so do i use eo to be ε0 = 8.85… × 10−12 F/m??
     
  4. May 4, 2010 #3
    Re: Capacitance using an axon.. :)?

    I have no idea how an axon membrane looks, but assuming it is a parallel plate capacitor then you have the right equation. And yes, that is the right constant in SI units.
     
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