USING EXCEL SPREADSHEETS TO DETERMINE THE EFFICIENCY OF THE INCLINED PLANE

This paper describes a tool created with Excel spreadsheets to calculate the efficiency of the inclined plane. In developing the tool, two aspects have been taken into account: on the one hand, the theoretical model, on the other hand, the practical aspect of determining the efficiency. Theoretically, the efficiency of the inclined plane can be calculated if the angle to horizon and the coefficient of friction are known. Practically, however, to determine the efficiency, it is necessary to select a certain experimental setup. In this case, to calculate the efficiency, the parameters of the experimental configuration are taken into account. The tool presented allows the confrontation between the theoretical model and the results obtained from of a didactic experiment conducted with the simple equipments from school laboratories. Based on the comparison “theoretical model - experimental results” there is also described an approximate method for determining the coefficient of friction. In a spreadsheet, we have graphically rendered the dependence of the efficiency on the angle to the horizon for different values of the coefficient of friction in agreement with the theoretical model. In another spreadsheet, we have graphically rendered the dependence of the efficiency on the angle to the horizon from the experimental data processing. In another special spreadsheet, on the same graph, we have graphically rendered the curve resulting from the experimental data, together with the theoretical curve of the efficiency depending on the angle to the horizon. With the help of this spreadsheet, it is shown how the coefficient of friction can be determined by the overlapping the two curves. Using this tool, students can identify more easily the errors of method committed in a Physics didactic experiment. Other advantages of the classroom use of the tool would be the clarification of the concept of mechanical efficiency, rapid data processing and the familiarization with graphic representations. Moreover, starting from this tool, students can be encouraged to build their own Excel tools in order to solve Physics problems or to process experimental data without the need for advanced programming skills.