Materials: 1 block of Styrofoam ruler 20 cm of magnetic tape box cutter magnetic track for testing

Transcription

1 Maglev Car Design Objective: Design, build, and modify Styrofoam vehicles to race down a magnetic track at the fastest speed. Materials: 1 block of Styrofoam ruler 20 cm of magnetic tape box cutter stopwatch magnetic track for testing Background Information: Because of the design of the Maglev track, balance is probably the most important factor in the design of the car. If the car is not balanced well it cannot make a successful run down the track. Cars that are not balanced well tend to wobble, get stuck, or run into the sides of the track. Although Maglev trains are energy efficient because they minimize the friction between the train and the track, Maglev cars do confront problems with drag. Drag is defined as the retarding force acting on a body moving through a fluid (air is a fluid), parallel and opposite to the direction of motion. The drag force is also referred to as air resistance. Because real Maglev trains are designed to travel at extremely high speeds of around 280 to 310 mph, they encounter much more air resistance than ordinary vehicles. Have you stuck your head or arm out of a car window while you were riding down the interstate at 55 mph? The feeling of pressure against your hand is air resistance. Now compare that to a train going 300 mph! That s a lot of air resistance! Because the Maglev train is being pushed so hard by the air through which it is traveling, this force of drag slows it down and wastes some of the energy of the train. In fact, the reason that real Maglev trains cannot go even faster than they do is that at these speeds the trains must consume too much power to overcome drag. Engineers try to minimize the problem of drag by making the Maglev trains very aerodynamic. This means that the trains travel smoothly through air and that the fluid of the air can move easily over the train. Think about your hand out the window at 55 mph again. Would you feel more pressure if your had is in a stop position, palm out facing and stopping the airflow or if you extended your fingers towards the front of the car and the airflow. (see picture below)

2 As another example, suppose you are getting bored with this exercise and decide to make a paper airplane that you will throw to the back of the class. Would your airplane be more aerodynamic if it has a sharp point at one end and resembles a triangle or would it be more aerodynamic if it were in the shape of a square? Talk with your partner about the design you would choose. Although your car will obviously not be traveling at the top speed of the real Maglev trains, drag will be an important design factor to consider. You are now going to sketch your prototype for your ideal Maglev car. The sketch should include top, side, and front views. Consider these key questions: What shape should the car be? What shape do racecars have? Where should the magnets be placed to balance the car? How does the design reduce drag? Prototype Top Sketch - don t forget to label with measurements.

3 Prototype Side Sketch - don t forget to label with measurements. Prototype Front Sketch - don t forget to label with measurements.

4 Building Get your sketches approved by the teacher and then you will be given the materials to create your car. Testing As you build, you might want to test the car in the track to make sure it is balanced and will travel down the track. Once your car is built, test to make sure it travels down the track at the speed you want. Record these tests in the data table. Test Number Variable being tested Results Changes to design The Race Record your car s time and compute its speed. (Speed = Distance/time) Time of run (seconds) Distance of track (cm) Speed of car (seconds/cm)

5 Analyze Data Using the race data from your classmates, how does your car s speed compare to those of your classmates? How did your classmates designs affect their cars speed? Make a direct connection from a specific design and speed. Reflection Explain how your car s design affected the drag it created and the speed it obtained. Explain how the magnetic forces allowed your car to move down the track. What were challenges you experienced? How did you work through those challenges? What design flaws did your vehicle have? How would you redesign the car to correct these design flaws. What did you learn by designing this car?

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