Dimensions of a Rotating Box

In the December 2001 issue of The Physics Teacher described a unique way to use motion detectors. In "Obtaining the Length and Width of a Rotating Box with a Motion Detector," Tom Lough (Murray State University, Murray, KY) describes placing a cardboard box on a turntable and having it rotate. Aim a Motion Detector at the box and then graph distance vs. time as the box rotates. You get some interesting results, and there is a lot of geometry and trigonometry to be learned in the process of determining the box's dimensions from these graphs.