Predict drag forces for various dragster shapes

Students are assigned a car number.

The dragsters are then set in order on tables and each student assigns a drag force number (1-25) for each dragster on their data sheet. This number is based on the student’s pre-conceived concepts about the aerodynamics of vehicles.

Each student then places their CO₂ dragster in the Scout Wind Tunnel, and attaches their dragster to the drag hook of the Scout. The drag hook attaches to the front screw eye of the dragster.

Once in place, the student will turn the Scout on, and adjust the airspeed to its highest position. Students then observe the front drag force on the LED display of the Scout. This data is then recorded for their dragster on a class data sheet, along with a car number. Their dragster is removed from the Scout and the next student prepares their dragster for testing.

Students compare actual results of front drag to their predictions, and then write two short paragraphs about the difference between their predictions and the results. One paragraph should focus on dragsters they came closest to predicting correctly (why they were right), the other on dragsters they did not come close to predicting (why they were wrong).

Have students race their dragsters and analyze the results to see any correlation between the amount of drag and the dragster times. You may also want to have students measure the mass of their dragsters and see if that has a closer correlation to times than does frontal drag.