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Homework Help: NO 2 OBJECTS WILL EVER really TOUCH?

  1. Feb 22, 2009 #1

    1. The problem statement, all variables and given/known data
    When an object is placed on table, the particles in the object and the particles in the table never actually touch.

    2. Relevant equations
    In a short paragraph, explain how the field model can be used to explain why the particles never touch. Refer to the strengths of the fields, and describle how individual charged particles are influenced by and react to the fields.

    3. The attempt at a solution
    My answer is the electrons in the two objects will repel(due to strong electrostatic repulsion) each other, and it will take an infinite amount of energy for the electrons from the 2 objects to touch.
    I dont know how to relate to strength of the field, please help, thanks!
  2. jcsd
  3. Feb 23, 2009 #2


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    Homework Helper


    Perhaps you could begin with one electron from each object. You know their charges so you can calculate their E fields or just use F = kQQ/r^2 to get their repulsion force on each other. How close would you have to push them in order to get them to "touch"? There must be some estimate of the effective size of an electron available. Once you have worked out the force needed to make one electron touch another, you'll have to scale it up to object size somehow. Can you calculate roughly the number of electrons on the bottom surface of an object such as a dollar coin?
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