Van de Graff Generator: Electrostatics, why do objects repel the generator

In summary, when the van de graff generator is turned on, pie pans fly off because they become positively charged and are repelled by the positively charged dome. When foam peanuts are placed in the pan, they also become positively charged and are repelled by the pan. This is due to charging by conduction. When a person touches the generator, their body becomes negatively charged and their hair stands up due to attraction between the positively charged dome and the negatively charged body. This is due to the body being a conductor and the principles of electrostatics.
  • #1
jamba88
9
0

Homework Statement



a) Why do pie pans fly off the Van de Graff Generator when turned on?

b) When foam peanut are placed inside a pie pan with the Generator turned on, what causes the foam peanuts to fly out?

c) Why does a person's hair stand up when they touch the generator?

Homework Equations


No relevant equations

The Attempt at a Solution


I'm not sure if my answers are correct or if I'm elaborating enough. Like should I talk about conductors/insulators...charging by conduction/induction.

a) Since the van de graff generator's dome is positively charged and the the pie pans tend to be positively charged, then the pans fly off because like charges repel.

b) The foam peanuts are insulators. The van de graff generator transfers charge to the pan, leaving it positively charged. This is charging by conduction. The pan transfers the charge to the foam peanuts. The foam peanuts fly off the pan because they are both positively charged and so the peanuts repel the pan.

c) Hair stands up when a person touches the van de graff generator because the body is a conductor. Postive charge moves freely through the body into the hair making it stand up.
 
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  • #2
The body is negatively charged and the dome of the generator is positively charged, so they attract each other.
 

1. How does a Van de Graff generator work?

A Van de Graff generator uses a motor to turn a belt that rubs against a rubber roller, creating static electricity. The static electricity is then transferred to a metal sphere or dome, which can be used to create electrostatic effects.

2. Why do objects repel the Van de Graff generator?

The Van de Graff generator creates a large amount of static electricity on its metal dome or sphere. This static electricity creates an electric field around the generator, which causes objects with a net positive charge to be attracted to it, while objects with a net negative charge will be repelled.

3. How does the size of the Van de Graff generator affect its electrostatic effects?

The larger the Van de Graff generator, the greater the surface area for static electricity to build up on. This results in a stronger electric field and more powerful electrostatic effects. However, the size of the generator also affects how much charge it can hold, so there is a limit to how large it can be.

4. Can a Van de Graff generator be used for practical purposes?

While the Van de Graff generator is mainly used for educational and demonstration purposes, it can also be used in certain industrial applications such as removing dust particles from air or for coating objects with a thin layer of paint or powder.

5. Are there any safety precautions to take when using a Van de Graff generator?

Yes, it is important to handle a Van de Graff generator with caution as it can produce high voltages. It is recommended to wear protective equipment, such as gloves, and to avoid touching the dome or sphere while the generator is in operation. It is also important to keep the generator away from any flammable materials and to use it in a well-ventilated area.

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