Professor Richard G. Born, from Northern Illinois University, devised an experiment to study hysteresis, the delay of time between a force being placed upon a system and the exhibited reaction. Born placed a 7 inch rubber band on a Vernier Dual-Range Force Sensor, with a Motion Detector placed on the floor below the rubber band. He extended the rubber band downward, pulling it with his hand, and released it upward, loading and unloading the rubber band. The Motion Detector recorded the position of his hand. During the five-second trial, Born sampled the extension distance and the magnitude of the force applied to the sensor.
To analyze the results, Born compared the measured force in Newtons, with the extension of the rubber band in meters. Students could see that the rubber band did not obey Hooke’s law, resulting in a non-linear relationship. Also, there was more force applied during the loading than the unloading of the rubber band, indicating that the system lost energy. This is represented in the space between the loading and unloading curve on the graph. Using the Integral function of Logger Pro, it was possible to determine the area between the loading and unloading sections of the graph, and to quantify the energy loss in Joules (N·m).
Net work done on rubber band during extension and return