Photoelectric Vending Machine

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Photoelectric Vending Machine

• Nathan Miller
• Univ. of Wisconsin
• Eau Claire

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Table of Analogies
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• Basic classical exchange
• Money in ? Chocolate out
• A class has a certain amount of money, they
  should be able to buy a certain amount of
  chocolate

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• Say you have class of 100 students, with 65
  dollars between them. They should be able to buy
  6500g of chocolate.
• But if they each have 0.65 and each walk by the
  vending machine, they dont get a single candy
  bar.
• This is like shining red light on the surface
  no matter how much you shine, no electrons is
  emitted.

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• Now say you have a class of 10 students, and each
  has a dollar.
• They can now buy 1000 grams of chocolate in total
• This time they can in fact buy the candy bars,
  but there is no energy left over.
• This is like blue light at the critical frequency
  electrons are ejected, but no KE is left over.

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• Finally, you have 2 people who have 1.50 each.
• They can buy the candy bars, and each has 50
  cents left over.
• This is like ejecting electrons and giving them a
  certain amount of kinetic energy.

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• If you have a vending machine with 65 cent candy
  bars or 1.10 candy bars, these would correspond
  to different work functions.