Motocross by Tamera, Tara and Samantha

We love the thrill of a breathtaking motocross jump and wanted to learn more about nailing a safe landing. We noticed that experienced racers try to land jumps with both wheels. Our question: How does my body position affect my jumps?

What did we do?
We practiced jumping with our body in three different positions at take-off: leaning slightly forward, leaning slightly backward and staying centered. While Tamera practiced the jumps, I used a video camera to record her body position and landing. We analyzed the video to see which body position was most effective.

What did we find out?
We found that when Tamera leaned back she landed on the rear wheel, which slowed her down. When she leaned forward she landed on the front, which caused her to lose some control. When she stayed centered she landed on both wheels and lost very little time. She used this knowledge in her next race and came in first place!

What can you do?

• Do you have a bike with gears? Count the number of teeth on the different gears and see how that relates to how fast the back wheel spins when you pedal.
   
  
• If you were shopping for a new bike what features would it have? Design the ultimate bike and think about things like wheel size, distance between wheels and weight.
   
  
• Use this motocross investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!
   
  

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