Engenharia de produção mecânica

Your Challenge
Build a car that goes really fast and really far (at least four feet, that is).
Oh, by the way, your power source is a rubber band, and your car can only have two wheels. Start your engines!
• 2 compact discs (CDs)
• Corrugated cardboard (one piece about 5 1/2 inches square)
• 2 faucet washers (Size: 1/4 inch
Large)
• Poster putty (1/4 package—buy the tackiest available)
• Rubber bands of different lengths and widths
• Ruler
• Scissors
• Tape (masking or duct)
• 1 wooden skewer (buy the thinnest available)
Materials (per car)*
1
2
3
4
5
6
17
challenge 1
Rubber Band Car
Unit Cars, cars, cars
2
* For information on where to get these materials, see page 6 or visit pbskidsgo.org/designsquad/engineers.
Build
Notch the body. Turn the cardboard so that, as you hold it flat, the corrugations run right and left (i.e., not forward and back). Cut across the corrugations and make a 2-inch-wide and 1 1/2 -inch-deep notch in the center of the side. Throw away the piece you’ve cut out.
Make the axle. Slide the skewer through the cardboard, close to the outer edge. Make sure the axle sticks out the same amount from each side of the body.
Modify the axle. Find where the skewer goes across the notch. In the middle of this section, wrap a small piece of tape to make a “catch” for the rubber band.
Assemble the wheels. Slip a washer into the center hole of a CD. Slide the washer and CD onto the axle, leaving lots of room between the wheel and cardboard. Put poster putty on each side of the washer to join the CD, washer, and axle REALLY TIGHTLY TOGETHER. The wheel and axle should now rotate together. Make the second wheel the same way.
Attach a rubber band. Choose one of the rubber bands. Tape one end to the cardboard at the end opposite the axle.
Power your car. Wrap the unattached end of the rubber band over the catch.
Turn the axle several times. You’ve given the rubber band potential (stored) energy. When it unwinds,