Van de Graaff generator? adding a electron?

In summary: I am in a dead end right nowSo there's more voltage in the first sphere than in the second...Nevermind I figured it out thanks though fr your help
  • #1
graphicer89
55
0
Van de Graaff generator? adding a electron??

Homework Statement




A)If a Van de Graaff generator is charged to 5,000 volts, how much energy does it take to add and additional electron to the charge on the sphere? If the charge of an electron is -1.6 x 10 ^-19...

B) How would the voltage of the generator in the part A compare to the voltage of a larger Van de Graaff generator with the same amount of charge? To which generator could an electron be addded with the least expenditure of energy?



Homework Equations



Are there any equations i can apply?

The Attempt at a Solution



A) I guessed but i don't know if I am right or wrong...i multiplied...

5,000 v x -1.6 x10^-19 C = -8 x 10^-16 energy but i think that's wrong can you please help me with the calculations? i don't know to multiply or divide...


B) I need to do A first to understand B...but my guess is that the voltage is the same but the force or work to include a electron would not be much in a larger generator. Its easier to add a electron to a larger Van de Graaff generator with the least expenditure of energy...
 
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  • #2


graphicer89 said:
A) I guessed but i don't know if I am right or wrong...i multiplied...

5,000 v x -1.6 x10^-19 C = -8 x 10^-16 energy but i think that's wrong can you please help me with the calculations? i don't know to multiply or divide...
-8 x 10^-16 Joules. Joules are the units of energy. If you'd written that, it would be correct. (You used the formula [itex]U = qV[/itex])

graphicer89 said:
B) I need to do A first to understand B...but my guess is that the voltage is the same but the force or work to include a electron would not be much in a larger generator. Its easier to add a electron to a larger Van de Graaff generator with the least expenditure of energy...
If the voltage were the same, the work required would be the same. But the voltage is not the same. Here's a hint: what do you know about capacitance?
 
  • #3


diazona said:
-8 x 10^-16 Joules. Joules are the units of energy. If you'd written that, it would be correct. (You used the formula [itex]U = qV[/itex])


If the voltage were the same, the work required would be the same. But the voltage is not the same. Here's a hint: what do you know about capacitance?

Honestly nothing...but this is kinda like earth..earth is so large that it consumes an infinite amount of energy and it never over flows..etc...so I am thinking...would it require more energy to add a electron to a small generator because its more compact?...i really don't want to go off topic...
 
  • #4


graphicer89 said:
Honestly nothing...but this is kinda like earth..earth is so large that it consumes an infinite amount of energy and it never over flows..etc...so I am thinking...would it require more energy to add a electron to a small generator?
Not actually an infinite amount of energy, more like so-large-that-for-most-cases-it-might-as-well-be-infinite. But anyway: yes it would require more energy to add an electron to a small generator, now can you figure out why? Go back to your references (textbooks, notes, whatever you have) and look up some information on capacitance if you need to.
 
  • #5


diazona said:
Not actually an infinite amount of energy, more like so-large-that-for-most-cases-it-might-as-well-be-infinite. But anyway: yes it would require more energy to add an electron to a small generator, now can you figure out why? Go back to your references (textbooks, notes, whatever you have) and look up some information on capacitance if you need to.

This is what i found...

The electrical potential energy of a charged particle is increased when work is done to push it against the electric field of something else that is charged. Just as work is done to compress a spring work is done in pushing the charge against the electric field of the sphere. This work is eqqual to the energy gained by the charge.
 
  • #6


OK, that's true, but surely there must be more than that? (You don't need to post it here, but you should read it yourself!) Especially keep your eyes open for a formula involving voltage that has to do with capacitance.
 
  • #7


diazona said:
OK, that's true, but surely there must be more than that? (You don't need to post it here, but you should read it yourself!) Especially keep your eyes open for a formula involving voltage that has to do with capacitance.

well actually what i tried looking but i just feel like I am in a dead end right now
 
  • #8


So there's more voltage in the first sphere than in the second...
 
  • #9


Nevermind I figured it out thanks though fr your help
 

What is a Van de Graaff generator?

A Van de Graaff generator is a device that is used to create static electricity. It consists of a large metal sphere or dome connected to a motorized belt that runs through two pulleys. The belt carries electric charges from the bottom of the generator to the top, where they accumulate on the sphere.

How does a Van de Graaff generator work?

A Van de Graaff generator works by using a motorized belt to separate electric charges. The belt carries positive charges from the bottom of the generator to the top, while negative charges are left behind at the bottom. This causes a build-up of electric charges on the metal sphere at the top of the generator.

What are the practical uses of a Van de Graaff generator?

A Van de Graaff generator is commonly used in scientific demonstrations to show the effects of static electricity. It can also be used in particle accelerators to produce high-energy particles for scientific research. Additionally, Van de Graaff generators are used in the production of x-rays and in some medical procedures.

Why is it important to add electrons to a Van de Graaff generator?

Adding electrons to a Van de Graaff generator helps to maintain a balance of electric charges. The motorized belt continuously removes positive charges from the bottom of the generator, so adding electrons helps to keep the generator functioning properly. If there is an imbalance of charges, the generator may not work as intended.

Is it safe to add electrons to a Van de Graaff generator?

Yes, it is safe to add electrons to a Van de Graaff generator. The process of adding electrons does not involve any dangerous materials or procedures. However, it is important to follow safety precautions when using a Van de Graaff generator, as the high voltage produced by the generator can cause electric shocks.

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