Aurora employs another physics trick to help her win. As a race car speeds down the track, it experiences drag, or air resistance. “The force of the air hitting the front of your car pushes the car backward,” says Granade. As the air passes over the rear of the car, it forms swirling eddies that create more drag.
To reduce this resistance, Aurora often follows inches behind another car—a technique called drafting (see Getting a Boost). The car in front pushes air out of the way, says Aurora. “It creates a tunnel of sorts,” she says. With both vehicles so close together, air moves around them as if they’re a single car. That reduces drag on both cars so they can both move faster.
The two drivers cooperate only for a short time. “It’s a team sport until the last few laps,” says Aurora. “Then it’s just you and the car, and everyone else is your enemy.” The rear car might use the extra momentum it’s gained from drafting to zip around the lead car. From then on, it’s a battle to the finish.