The Madness of Stirring Hot Chocolate

Physics of the Mundane

Adam Johnston

Stirring hot chocolate creates an interesting and not-easily-explained phenomenon^[1].  After stirring the hot chocolate mix into the water, the tone produced by tapping the metal spoon on the bottom of the cup is relatively low, but gradually raises pitch.  Stirring the hot chocolate again will restore the lower tone, but it will rise just as before.

Explain why.

You should have one partner.  Together, you make up a research group.  This is your most valuable asset.  Also in your favor are the following:

·        Several different cups.

·        Almost endless supply of hot chocolate mix.

·        Spoons.

·        Sources of hot and cool water.

In addition to explaining Awhy,@ explain what you are doing to answer the question.  That is, what is the method to your own madness?  Document this all in your notebook.

(Note: Your answer is not as important as your procedure.  Perhaps you should first guess at the answer, and then test your guess in as many ways as possible.  Continue with this process until you arrive at a “best guess.”)