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Homework Help: Green Pea Discharge

  1. Aug 13, 2006 #1
    I dont have a clue on where to start this as i dont know what other figures to use.

    Dry air will break down and generate a spark if the electric field exceeds 3x106N/C. How much charge could be packed onto a green pea (diameter 0.75cm) before the pea spontaneously discharges?
     
  2. jcsd
  3. Aug 13, 2006 #2

    Chi Meson

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    This is a quaestion about capacitance. You need to find how the capacitance of a single object (as opposed to parallel plates) is related to its surface area.
     
  4. Aug 13, 2006 #3
    any further help on this?
     
  5. Aug 13, 2006 #4

    Chi Meson

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    Do you have a textbook?
     
  6. Aug 13, 2006 #5
    no i dont,could you possible give me the equation?
     
  7. Aug 13, 2006 #6

    Astronuc

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    One has to calculate the charge that yields an electric field of 3x106 N/C on a sphere of diameter 0.75 cm.

    Then one should know the equation for the electric field at the surface of a sphere. This is an application of Gauss's Law. See - hyperphysics.phy-astr.gsu.edu/Hbase/electric/elesph.html (unfortunately site is down at the moment).

    Also -
    http://physics.bu.edu/~duffy/PY106/Electricfield.html (toward bottom of page),

    Worked example 4: Electric field of a uniformly charged sphere
    http://farside.ph.utexas.edu/teaching/302l/lectures/node18.html
     
  8. Aug 13, 2006 #7
    thank you for your help,are you any good with biology equations?
     
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