# Fifth Period

## First Time Here?

Go to the first strip and
see how it all started!

Join students Sophie, Tomás, Emma, and Marcus during Fifth Period! This STEM comic strip chronicles the exciting and often hilarious adventures of a close-knit group of four friends as they learn about science, technology, engineering, and math from their kooky, inspiring, off-the-wall science teacher, Mr. Kepler. When they're not in class, these kids love to explore the vast world of STEM on their own, launching weather balloons, programming computer games, and cataloging insects, sometimes with unpredictable and highly entertaining results!

Check back on the first and third Friday of every month for a new Fifth Period strip!

December 21, 2012

### Bernoulli's Principle at Work

What Mr. Kepler was explaining to Emma was the effect of Bernoulli's principle on aircraft, which states that with the flow of a fluid (like air), when the speed of a fluid increases, the pressure of the fluid decreases. Emma figured out that she wasn't getting enough low pressure above the wings of her aircraft to give her enough lift. She decided the solution was a faster air flow—more SPEED. We'll find out later if she was able to get enough lift!

Try it yourself—with paper airplanes, not the skateboard and glider!

You can see the effect of size and speed on an aircraft by using simple paper airplanes! Experiment like this: take a small paper airplane and a larger one that's been folded with thicker, sturdier paper. First test with light tosses, and then test with more powerful tosses. See which airplane goes farther in each case.

This experiment works even better if you have two differently sized toy gliders—look for them in a dollar store! When you toss them, which do you observe going farther, the large one or the small one? Can you explain what happens using Bernoulli's principle?