METHODOLOGICAL ASPECTS OF DETERMININGTHE COEFFICIENT OF KINETIC FRICTION OF WHEAT KERNELSON AN INCLINED PLANE

One of the most popular methods of determining the coefficient of kinetic friction between a pair of solid objects involves an inclined plane. However, manual measurements of the time taken by a particle to travel a certain distance (usually performed with a stopwatch) and the angle of an inclined plane (on a scale) are not always highly accurate or precise. The coefficient of kinetic friction has to be determined on the assumption that a particle moves in uniformly accelerated motion. The aim of this study was to analyse particles moving in uniformly accelerated motion on an inclined plane and to modify the method of measuring movement parameters. A mechatronic measuring device and a high-speed camera were used to monitor the movement of wheat kernels on a steel friction plate. The experimental variables were the distance between photosensors (length of the measured section) and the kernel’s position relative to the direction of movement. An analysis of the mean values of time taken by particles to travel different distances revealed that the particles were not moving in uniformly accelerated motion. The results indicate that the coefficient of kinetic friction of irregularly shaped particles cannot be determined reliably on an inclined plane. Several recommendations for modifying the test stand were proposed.