Curling by Mimi, Haley, Tara and Lauren

We're Mimi, Haley, Tara, and Lauren, and when we talk about curling, we don't mean hair! Curling, our favorite sport, is a sport in which you slide four heavy rocks down an icy surface at the center of a target. The team with the rock closest to the target's center scores a point. When we release the rock, we give it a little bit of spin, so it curves a little, or "curls." This got us thinking: How does the spin we put on the rocks affect where it goes?

What did we do?
First, we looked for the relationship between which way the curling rock rotated and the direction of its curl. Then we investigated the effect that sweeping has on the each rock's motion. (Sweeping is a curling maneuver that involves rubbing, or really sweeping, the ice in the rock's path, which melts the ice a bit.) We used a digital laser timer to gauge the speed of the rock, then measure the distance of the slide, either sweeping it or not.

What did we find out?
We compared the swept and unswept rocks of similar initial speed, and learned that all rocks, regardless of speed, glide farther when the ice in front of them is swept.

What can you do?

• Find a smooth flat floor space in school, such as in the gym or cafeteria. Make "curling rocks" out of plastic food containers (like Tupperware). Attach a handle to the lid, like a curling rock has, so you can slide the container along the floor and give it a spin at the same time. Now, a curling rock that spins clockwise veers (or, curls) to the right; one that spins counterclockwise veers left. Do these containers curl just like curling rocks on ice?
   
  
• Try an experiment with another object that spins... a flying disc. Most of us throw with our right hand, which gives the disc a clockwise spin. Try to find a way to throw it so it spins counterclockwise. What differences do you see in the disc's flight? Does it tend to veer one way or the other, depending on the spin? Is there no difference at all?
   
  
• Use this friction 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.