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Homework Help: Classic Static Electricity Balloon Example

  1. Jul 20, 2015 #1
    1. The problem statement, all variables and given/known data
    1. Explain why a balloon sticks to a wall after being rubbed on your shirt (remember the wall is not metal and does not have "free" electrons")
    2. Include a balanced force diagram that includes the electrical force and gravitational force (assume electrical force is twice the magnitude of gravitational force). Draw all three forces to scale

    2. Relevant equations
    Some things I don't understand. If a balloon attracts electrons from rubbing it on hair or a sweatshirt. Then it must have a higher electronegativity. But if we assume the balloon is rubber, a good insulator, doesn't this mean that the rubber objects should not accept electrons readily? Also, I'm having trouble understanding how the balloon can stick to the wall. Initially I thought that the balloon was attracting positive charges to align near the electrically charged balloon. But the question specifically reminds me that since the wall is not metal, the electrons are not free to move away from the protons.

    3. The attempt at a solution
    The attempt is in the questions i have
  2. jcsd
  3. Jul 20, 2015 #2


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    Homework Helper

    Being an insulator means that the material do not have free electrons available for conduction,
    but it can still remove electrons from other materials due to its high electron negativity.
    The charged balloon polarizes the molecules in the wall's material and thereby sticks
    to the wall.
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