In the early days of skateboarding, roller-skate wheels were attached to two-by-fours and then ridden down steep hills. It was enough of a challenge just to stay on!

The sport has come a long way, thanks to improvements in materials and the design of the boards. These new advances make all sorts of tricks possible.

It may seem that skateboarders have found a way to defy the laws of physics, but what they are really doing is using those laws to their own advantage.

Before we investigate the physics of skateboarding, let's watch some skateboarders in action. If you click on the video to the right, you will see some enthusiasts practicing at a specially designed park. The park contains slopes and banked surfaces that allow kids to perfect their techniques and stunts.

This video is part of an upcoming Riverdeep language arts product for grades 4-6, called Write for Your Life, which focuses on writing a narrative essay. It will become part of Riverdeep's Language Arts subscription beginning in the summer of 2001.

After you view the video, pretend that it was you who just spent the day skating at a skate park. Describe the experience in a couple of paragraphs. Your paper could include answers to the following questions:

• How did you begin your day at the skate park?
  
  
• What sort of people were there skating with you?
  
  
• What sort of tricks did you try throughout the course of the day? (Use a skateboarding glossary to make sure you are using all the right words.)
  
  
• How did it feel to perform such stunts?
  
  
• Were you ever scared to try a new trick?
  
  
• Did you fall down and hurt yourself?
  
  
• Is skateboarding worth the time and effort?

Watching a skateboarder perform a trick flawlessly can be an awe-inspiring experience. Skateboarders may not realize it, but they accomplish their tricks by working with the laws of physics.

The ollie is the most important trick to master because all other air tricks rely on being able to perform it.

The ollie is basically a jump during which the board stays flush with the feet. Perhaps you've seen skateboarders leap into the air with their boards seemingly attached to their sneakers. How do they do this?

The trick is performed by slamming the tail of the board to the ground before takeoff. If a skateboarder doesn't kick hard enough, the board won't get enough vertical rise. If we throw a baseball into the ground as hard as we can, it will bounce up. The same principle is at work here. If a skateboarder exerts enough force, the board will bounce up beneath his or her feet.

When the board is completely in the air, the skater slides his front foot forward, using the friction between his foot and the board's surface to drag the board higher.

Eventually, gravity takes over, and the board and skater together will begin to fall until they land.