Find out when DragonflyTV is on in your town.

This text is replaced by the Flash movie.

Speedskating by Sarah, Lisa, Ned and Eric

We're short-track speedskaters who want to melt the competition! We know that every fraction of a second counts, so we can't slow down at all while racing. That's why we're investigating how we should perform our turns: should we enter the turn in a tight, medium, or wide fashion to maintain speed?

What did we do?
We did three trials for each turn: tight, medium and wide. Tight means we started in close to the turn; wide means we started the turn in the outer lane. We timed each other using a stopwatch, and reported how "in control" we felt during the turn. To make sure we stayed in our lanes, we also recorded our paths on the speed skate-cam, Finally, we made a chart to show our results.

What did we find out?
Each of us had slightly different results, but there were some patterns. Most of us felt we had more control when we went wider, although Lisa said she felt more in control on the tight turn. Even though the tight turn is the shortest path, we didn't find our shortest times on that path, probably because we had to ease up to avoid wiping out. Most of us found that the medium turn gave us the right combination of speed and control. We learned that to make a tight turn, our skates had to push harder on the ice, but that we also were more likely to wipe out if our skates slipped.

What can you do?
• Get an old-style record turntable, and make a cardboard "record" to put on it. Make it about 12-15 inches across, or as big as will fit. How far out on the spinning disk can you set the penny before it slides away? Try it with other coins or objects, too.

• On an ice rink or roller rink, lay out some paper cups as markers for a half-circle turn. Then, skate fast towards the start of the turn, and try to follow the line of the cups as closely as you can. Try making the circle of cups smaller or larger. What do you notice when you try to skate fast around each size of turn?

• Can you run faster than you skate? Design a test to find out whether you can run faster than you can skate a distance of 20-30 meters, always from a standing start.

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

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

What's the record for fastest land speed in a car?