Why is the balloon sticking to the wall?

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Main Question or Discussion Point

When you negatively charge a balloon, by rubbing it on clothes, and then placing it against the wall, why doesn't the electrons move to the wall, causing the balloon to drop?

I would have thought the electron transfers to the wall - therefore an example of conduction.

Why is it induction and sticks to the wall, rather than conduction and the balloon falling down.
 
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  • #2
Nugatory
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I would have thought the electron transfers to the wall - therefore an example of conduction.
Why is it induction and sticks to the wall, rather than conduction and the balloon falling down.
The balloon is rubber or some other nonconductive material so the electrons cannot move freely through it. The attractive force between the electrons and the wall is not strong enough to drag the electrons through the balloon material so they stay put. Or in terms of Newton's laws: the net force on the electrons is zero because the electrostatic force between them and the wall is balanced by the force of the balloon material on the electrons; the balloon material is exerting a force on the electrons so the electrons are exerting an equal and opposite force on the balloon material; this force is pushing the balloon against the wall; and friction between the balloon and the wall keeps the balloon is place against the force of gravity.
 
  • #3
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The balloon is rubber or some other nonconductive material so the electrons cannot move freely through it. The attractive force between the electrons and the wall is not strong enough to drag the electrons through the balloon material so they stay put. Or in terms of Newton's laws: the net force on the electrons is zero because the electrostatic force between them and the wall is balanced by the force of the balloon material on the electrons; the balloon material is exerting a force on the electrons so the electrons are exerting an equal and opposite force on the balloon material; this force is pushing the balloon against the wall; and friction between the balloon and the wall keeps the balloon is place against the force of gravity.
I wonder why they can't explain it like this in textbooks. They just expect you to take it at face value. Even the high school teacher doesn't seem to know this explanation. He just knows that it's "induction". And then they expect you to solve problems, when they did 0 teaching.
 
  • #4
Nugatory
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well, induction is still needed - without it, there wouldn't be an attractive force between the electrons and the wall.
 

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