Automated system for measuring the static friction coefficient. A device for learning activities

A device for determination of static friction coefficient is presented, which has been designed to improve the data acquisition experience, without sacrificing its educational content. The system, based on the measurement of the critical sliding angle for an object on an inclined plane, it uses a position sensor, which removes the reaction time factor from the measurement. An ARDUINO UNO microcontroller allows for the acquisition and recording of the position and plane inclination angle simultaneously, this allows for determination of the critical sliding angle. Additionally, an automatic mechanism to continuously vary the plane angle by means of a non-solidary mechanical connection is included, thus reducing abrupt movements or the transmission of vibrations from the motor to the surface upon which the measurement is made. Using the proposed system, friction coefficients with high degree of reproducibility are obtained, with values that do not exceed a 3% rate of error for measurements. The system was tested, using the same methodology, on surfaces of different types, and satisfactory results were obtained. As a reliability test, the device was used in a set of experiments to determine the effect of mechanical vibrations on the results.

Keywords
Static friction coefficient; inclined plane; automation with ARDUINO; teaching laboratory practices