Temporal description of colision forces: a didactic model for physics laboratory aided by embedded system

Abstract In this study is modelled an experiment for physics laboratory to describe the temporal force in a ball collision. The model employs a piezoeletric sensor, a modest programable circuit (Arduino) connected to a computer and a vertical support to release the ball in free fall. A C-language program was created to read the sensor signal and calculate the force intensity as well as to calibrate the system. The processing algorithm employing the physical laws is presented as the source-code. After the collision a 120 μs resolution force x time table is provided, allowing the student to plot the graphic of force or to do numeric analisys, verifying the momentum and energy conservation laws. Performance tests are discussed showing that the model offers very good accuracy, thus validating the calibration method. At low cost and simple assembly, this embedded system, that is, program-controlled, allows a detailed exploration of force during the colision. As well it can be extended to another phisics effects, merely changing the sensor and ajusting the program.