How Does That Work?: The Drinking Bird

Have you ever seen these little toys around?  You dip their beak in a cup of water, then the bird swings up and when he gets thirsty again, he'll dunk down and get some more to drink.  He'll do this over and over again. 

Can your students figure out why? 

The short answer has to do with evaporative cooling and vapor pressure.  For a longer answer, check here.

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How Does That Work is a series of products and demonstrations that you can present to your students and challenge them to explain the science of how they work. Make sure you decide ahead of time what you'll accept as a valid explanation - can it be printed straight off the internet, written in the student's own words, or does the student need to be able to explain it to you conversationally? What will a valid explanation earn the student - a prize, extra credit, a feeling of goodness?