Science Fun in the Snow!
Racing on Ice
Skaters can reach speeds of 50 km/h, while the best runner can reach 40 km/h. Why the difference? The range of possible speeds on different surfaces is usually explained by friction. However, when it comes to ice, scientists don’t always agree. See the sidebar for some of the theories explaining why we slide on ice.
- small toy race car
- cookie sheet
- wood board
- cover from a large plastic container
- adhesive tape
- sheet of paper and pencil
Why do we slide on ice?
Many scientists believe that we don’t actually slide on ice, but rather on a thin layer of water that covers the ice surface. The water is formed from the friction of objects rubbing against the ice or snow. Other scientists believe that the layer of water is created by a weight pressing on the ice. Yet another theory suggests that water molecules on the surface of the ice vibrate, and these vibrations reduce the friction between an object and the ice, making the object slide.
No matter which theory you believe, there is no denying that skates are the best equipment for speeding down the ice!
Start your engines!
- Run the cookie sheet under the kitchen tap. Once the sheet is wet, place it in the freezer.
- Cut a piece of string the same length as the shortest of your race courses (i.e., either the cookie sheet, wood board, or the plastic cover).
- Make a scorecard by drawing three columns on the sheet of paper, and labeling each with a race course surface (i.e., ice, wood, plastic).
- Place the box where you plan to hold your races.
On your mark, get set, go!
- Place one end of your first race course on the box.
- Tape the string along the length of the surface.
- Set your stopwatch.
- Place your car at the top of the course.
- Start the stopwatch as soon as you release your car.
- Stop the stopwatch as soon as the car reaches the end of the string. Record the time on your scorecard.
- Repeat the experiment with the two other race course surfaces.
- Racing on Ice
And the winner is…
Which surface allowed the car to travel the fastest? Compare the textures of your race course surfaces.Back to top