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Ice Bike by Bob and Brennan

We're Bob and Brennan, and we're into a very cool, very slick sport: ice biking! Our school holds an annual ice bike race, and goal is to design and build the winning bike. We know we want to modify one of last year's top models by adding studs to the tires. The studs will give us traction, kind of like cleats do on shoes. Our DragonflyTV question is: How many studs should we add for maximum speed on ice?

What did we do?
We grabbed three rubber tires, and installed 50 studs in the first, 100 studs in the second, and 150 studs in the third. Then we recorded the time it took to go around a 200 meter ice track once from a complete stop, doing several trials for each tire.

What did we find out?
For the conditions of the track (wet and slushy), we found that the 100-stud tire gave us the shortest race time, and the most control. We learned that more isn't always better!

What can you do?
• Do a friction study of your own. Get a board (like a plank or shelf), and some household objects to slide down the plank. Try things like a hockey puck, a tissue box, a soup can, a CD case, anything that will slide, not roll. Lay the plank flat, set the object at one end, then slowly lift that end until the object begins to slide down the plank. Measure how high you have to raise the plank before each object slides. Predict which things will slide at lower angles, and which at higher angles, before you begin.

• If you live where it snows, get outside with your snow sled and do some science! Find a good sliding hill, and make a sledding track in the snow. Do an experiment to see how they weight of the cargo in the sled affects how quickly it slides down the track. Start with an empty sled, then fill it with more and more weight. Use a stopwatch to measure the times carefully. Don't have snow where you live? Try the same thing on a grassy hillside!

• Use this bike investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!

 SciLinks More on friction. Go to the DFTV Boards, and tell us about your science investigation.