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Ready, Jennifer. Now let's find out how surface area affects drag.

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Your teacher will give each group a copy of the disc patterns.

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From the lesson guide, select and construct five discs.

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Look at one of the discs. What do you think the area is?

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Make a prediction and write it down.

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Now, calculate the actual area.

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What is the difference between your prediction and the actual area?

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Are you close?

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Repeat these steps for each disc.

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Before beginning the experiment, construct the test track.

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Choose any disc and place it on the front of the test vehicle like this.

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Place the vehicles on the start line.

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Make sure the string is nice and tight.

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Predict the distance that the test vehicle will travel when the fan is turned on.

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And write it down.

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I predict it will travel about 42 centimeters.

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I predict it will travel 50 centimeters.

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Turn the fan on high for approximately 10 seconds.

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This is only a suggested time.

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Your time will depend on the fan speed and test vehicles.

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Now, measure the distance that the test vehicle moves backward

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and record it on the data sheet.

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Calculate the difference between the predicted distance and the actual distance

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and record your answer.

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How did you do?

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Now, test the other discs.

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Now that we've gathered our data, let's create a graph

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that shows the relationship between frontal surface area and distance.

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Could I have one member of each group to come up and graph their data?

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Great job, guys.

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Let's look at the graph and answer some questions.

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What kind of graph is it?

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Do you see a correlation?

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Do you see a correlation?

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If so, what kind is it?

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Which surface area produced the least amount of drag?

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Now let's put it all together.

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Look at the data from the first experiment you did.

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Which shape had the least amount of drag?

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This shape?

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Now look at your data from the second experiment we did on surface area.

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What did you find out about the surface area and drag?

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Based on your results,

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which of these four tetrahedrons should have the least amount of drag?

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How can we test your predictions?

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Put the shapes on the drag stand and see what happens.

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Great, let's do it.

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We'd like to thank the AIAA student mentors from North Carolina State University.