Have you ever noticed that the wheels in car commercials sometimes look like they’re spinning backwards?
Is this some sort of fluke in the tire design, or is something else going on?
In this lesson, students apply the formula for the circumference of a circle to convert between a car’s speed in miles per hour and the number of rotations its tires make every second. By comparing this rotational speed to the frame rate of a video camera, they’ll come up with rules to determine what makes a spinning wheel sometimes look like it’s moving in the opposite direction of the car sitting on top of it.
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