2 Conductive Spheres conected to ground - Physics

Discussion in 'Homework Help' started by Rubnalq, Nov 18, 2013.

  1. Rubnalq

    Thread Starter New Member

    May 11, 2012
    Hello and good day. I hope you can help me understand this problem since as of now I can't really solve it:

    I have a conductive Sphere (radius R), inside (but separated) a thick layer of a second conductive Sphere with inner radius 2R, and external radius Re.

    I'll give you an image:


    My problems start with this:

    The space between the Spheres is filled with a charge of a certain fuction of density p(r) for r between R and 2R, and then they are conected to ground (as in the picture) I have to determine value of charges in all surfaces (internal and external of the external sphere and external of the internal sphere).

    I have studied theory from Tipler & Mosca's physics, so I thought I may need a gauss surface? but which one and where?

    My biggest problem is the Ground connection... I can't seem to understand what effect does the ground connection to the charges. (I didn't found a single example of a ground connection like this in the book...)

    I would apreciate if you help me understand what kind of interaction goes between the space and the spheres and the Ground with the spheres, thank you.

    I'm sorry if I seem to be too global but I don't quite get the interactions.
  2. WBahn


    Mar 31, 2012
    The ground connect means that any amount of charge can flow onto or off off the two conductive spheres and since they are connected to ground potential, which we will call 0V, that you know that the voltage on the two spheres is also 0V.
  3. anhnha

    Well-Known Member

    Apr 19, 2012
    Is ground here Earth ground?
  4. WBahn


    Mar 31, 2012
    Can be but doesn't have to be. Ground simply means a connection to something that can supply whatever charges is needed in order to keep whatever it is connected to at the same potential as it.