A sailboat moves along the water in a very smooth, almost effortless manner. They work by harnessing the wind in the sail for power, and it is possible to demonstrate that movement at home with a wind-powered car. They're extremely simple to make, and wind-powered toy cars are pretty fun to race. First, you'll need a few simple materials, and then you'll need a source of wind--which will be played in your home by a portable fan.
Design the base of the car. Draw the base on the cardboard. You can make it any size or shape that you'd like, but make it at least 4-inches by 6-inches.
Trace the base of your glass on the cardboard four times. Make sure these are traced smoothly, as they will become the wheels.
Cut out the pieces of cardboard. Make the cuts as smooth as possible.
Turn the base upside down and draw a pair of parallel lines on it. These lines will be where the axles go, so make them perpendicular to the sides, and put one in the front and one in the back.
Glue the straws to the bottom of the vehicle. Trim off any excess straw.
Pierce the exact center of one of the wheels with one of the skewers. Glue the skewer in place at the end of one of the wheels. Repeat with the other skewer and another wheel.
Slide both skewers into the straws at the bottom of the car base.
Pierce the center of the other two wheels with the exposed ends of the skewers. Glue them into place, but be careful not to glue the straw to the skewer. Slide the wheel close to the car, so you can trim off any excess axle.
Pierce the middle of the car base with a skewer and glue it into place poking upward. The bottom of this skewer should more than clear the floor.
Design and draw a sail on the construction paper. A larger sail will catch more wind, but you can make it any shape that you want. Mark the point at the top and bottom of the sail where it will attach to the mast.
Slide the sail into place on the mast. Pierce the marks and make it curve forward. If the sail starts to slip, tape it in place.
If the car base bows when the sail is attached, use a few skewers to reinforce the middle of the car.