Snowboard superstar

Science World, Jan 21, 2002

When it comes to downhill racing, friction also slows Olson's speed. To overcome friction, she relies on snowboard design. The base, or bottom, of a snowboard is covered with P-Tex, a high-density polyethylene, or light plastic, that's easy to lubricate with wax. Snowboards are waxed to create a smooth, fast trip down the slopes.

The less contact there is between surfaces, the less friction. That's why Olson "craves" her snowboard when whipping turns. She angles the board so only one edge slices through snow, like a knife slicing butter.

The biggest source of friction is air. When Olson flies out of a halfpipe for an "air-raising" stunt, air pushes her back and slackens her speed. She crouches and "hugs" her board to reduce the surface area of her upright body pushing against air. The result: slick sailing, plus high points for a smooth stunt.

hands on science

Race Your Own (Mini) Snowboard

What speeds up a snowboard and helps it overcome friction? Design one and find out.

YOU NEED

2 pieces of stiff cardboard 22 x 28 cm (8.5 x 11 in.) each * strip of cardboard 2.5 x 5 cm (1 x 2 in.) * tape * books * pencil and paper

TO DO

1. Tape the two pieces of stiff cardboard together to make a ramp that is 56 cm (22 in.) long.

2. Make two stacks of books, one 30.5 cm (1 ft)-high and the other 15 cm (6 in.)-high. Place the stacks side by side. Prop the cardboard on the books at an angle.

3. The cardboard strip is your "snowboard" Hold the strip at the top of the ramp and then push it down.

4. How can you make your snowboard go faster? How can you reduce friction? How does your snowboard's shape and weight affect its speed? Would bending the board make it move faster?

5. Think about various materials to add to your snowboard to increase its speed (tape, petroleum jelly, etc.).

6. Test your improved snowboard. Repeat step 3 three times.

DON'T STOP NOW!

Compare your snowboard to those made by your classmates. Race your snowboards.

CONCLUSION

What design factors help make a speedy snowboard?

Cross-Curricular Connection

History: Research the history of the Olympic games. Report on one aspect. For example: women competitors, the Winter Games, obsolete events, politics, etc.

[ILLUSTRATUON OMITTED]

Did You Know?

* Beginners prefer soft, flexible snowboards because they're easier to maneuver--pressure on one side will turn the snowboard. Stiffer snowboards tend to resist that pressure and move in a straight line. That makes them ideal for racing downhill.

* Snowboarders generally use longer snowboards in the powdery snow of Colorado compared with the harder, more densely packed snow on the East Coast. A longer snowboard spreads weight over a larger area so it sinks less in the soft snow.

* Areas buried in snow seem unusually quiet because snow absorbs sound waves. However, as snow becomes more packed it absorbs less sound.

National Science Education Standards

Grade: 5-8: motions and forces abilities of technological design

Grade 9-12: motions and forces * abilities of technological design

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