Driving along an unfamiliar road, you see the upcoming light turn from green to yellow. Decision time … do you proceed through the yellow, do you apply the brakes, or do you speed up? The decision is dependent on variables such as the yellow light time, your response time, and your speed. Creating a model for making that decision is an excellent exercise for students in applying their knowledge of kinematics. The yellow light problem was first introduced in operations research and has been reframed in a number of traffic, engineering, and physics papers and curricula. Most recently, I have used the yellow light problem in an introductory physics class for life science majors (IPLS) and had students present “yellow light models” for biological systems. This approach has generated interest, physics relevance for students, and novel insights into biology for me.

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Number of students who responded to the extra credit prompt: In year 1, 17 students of 98 enrolled responded. In year 2, 21 students of 119 enrolled responded.
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