You’ve probably seen pictures of cute old-fashioned windmills. Today’s windmills aren’t as cute and charming, but they’re a lot bigger and stronger — and make lots of electricity for us. They’re called wind turbines, and they are HUGE. Their propeller blades can be up to 200 feet long, and can slice through the air at 180 miles an hour! As the blades spin in the wind, the machine turns that energy into electricity, which then flows into the “grid” and through the wires to our houses. You know how a light bulb uses around 60 watts? These wind turbines can generate 1 million watts, enough power for hundreds of houses at once. A whole “wind farm” of turbines can power many towns. Now you’d just better hope the wind keeps blowing!
Wee ones: Put a piece of paper on the table, and blow it. How far can you make the paper move?
Little kids: If your home uses 2 light bulbs total, but you build a little windmill that can power 6 more bulbs, how many bulbs can you light now? Bonus: The 6 closest turbines in the photo have 3 blades each. How many blades do they have in total? Try to count up by 3s!
Big kids: If the tower holding up the blades is 263 feet tall to the center, and the blades are another 100 feet long, how high off the ground could you swing if you could ride on the tip? Bonus: Just 1 wind turbine can capture enough wind power to run about 500 houses! If you build a farm of 30 turbines, how many houses can you power? (Hint if needed: How many could you power with just 3 turbines?)
Wee ones: Try it! See if the paper moves farther on your 2nd try than on your 1st.
Little kids: 8 light bulbs. Bonus: 18 blades: 3, 6, 9, 12, 15, 18.
Big kids: 363 feet. Bonus: 15,000 houses!
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.