- Provide solutions to balance an aerodynamically imbalanced race car
- Race Car Adaptations Resource Sheet (for reference)
- Balancing Backwards and Forwards Activity Sheet
- 1 sheet of paper
- Small weights such as paper clips or coins
- Assembled race cars from Lesson 1
- Card stock
- Make copies of each resource and activity sheet for each student in your class.
Think: How does design affect a car’s aerodynamic balance?
Step 1: Recall and review the race car adaptations that NASCAR engineers use to influence aerodynamics during races (Race Car Adaptations Resource Sheet). Discuss the fact that the fine-tuning of these parts, with minor adjustments to size, shape, material, or position, affects the balance of aerodynamic forces acting on a vehicle.
Step 2: Have students consider who makes these adaptations. Explain that many people are involved in the design, development, and adaptation of race cars. The life of a race car begins in a workshop. The shop foreperson plans and manages diverse jobs to get the car created and assembled. Different kinds of engineers and other car experts work together in the workshop to build the cars that will race on the track. Mechanical engineers develop new tools and engines as well as design race car adaptations, while test engineers review those adaptations in special research centers. Manufacturers bring the adaptations to life, and the pit crew engineers make additional changes to the adaptations, which occur right on the track! All of these careers rely on math and science to determine how to best adapt cars for optimal aerodynamics, safety, and speed.
Move: How does the force of weight affect a vehicle’s balance?
Step 1: Explain that air pressure works like additional weight on a vehicle. The aerodynamic forces that exert pressure on cars are even stronger at higher speeds. Tell students that by studying how aerodynamic forces influence a race car’s balance, engineers make decisions about the mechanical forces they will manipulate on the race car.
Step 2: Reinforce the downforce demonstration from Lesson 2: Downforce (MOVE: Step 2). To prepare for the demonstration, have students fold 1-inch flaps along the two shorter edges of the paper, then have them turn the paper over in order to fold two more 1-inch flaps along those same edges. Have them blow air beneath the paper and remind them that slow-moving air above the paper creates high pressure, and fast-moving air below the paper creates low pressure, the combination of which causes the paper to sag.
Step 3: Next have students add weights, such as paper clips or coins, on top of the folded paper. Ask them to describe what they notice. The weights have the same effect on the paper as aerodynamic forces— both forces cause the paper to sag. Just as altering airflow changes the balance of the paper, moving weights changes the balance of the paper.
Build: How does the weight distribution affect a vehicle?
Step 1: Remind students that imbalanced forces can affect steering, so race car engineers work to achieve mechanical balance through weight distribution. Challenge students to come up with an experiment to test the effect of mechanical balance on a moving car.
Step 2: Have students form pairs or small groups. Distribute the Balancing Backwards and Forwards Activity Sheet. Go over instructions with the class, and have students complete the activity.
Step 3: Review the results of the experiment as a class. There may or may not have been an observable effect. Ask:
- Were you surprised by the results? Why?
- How is this model like a race car? How is it different?
- How might your results apply to NASCAR, and why might they not?
Depending on factors such as the angle of their ramp, students may observe that back-heavy cars traveled farther than others. However, potential energy plays a role in the ramp test, which is one key difference between this model and real race cars— which race on a flatter track.
Team Up: How could you test the effects of balance on a real-life race car?
Step 1: Have students form small groups. Tell them they will write a proposal for an experiment to test the effects of balance on race car performance in the real world. Reports should include: A) a description of the race car; B) a list of materials or facilities that they will need; C) basic steps of the experiment; and D) an explanation of the data they intend to collect.
Online Simulation: Visit scholastic.com/nascarspeed/drive for an online interactive simulation that will allow students to apply aerodynamics principles to design, then drive their own race cars!