Developing practicum device using magnetic sensor for circular motion at Senior High School

Abstract

This research aimed to develop a circular motion practice device for senior high school. The device visualized uniform circular motion concept. The applied method of this research is an ADDIE (Analyze, Design, Development, Implementation, and Evaluation) development research method. The device has been designed which consists of a motor that drives a propeller with a magnet on it and hall effect A1319E magnetic sensor detects every rotation of the magnet. The final result obtained the number of magnetic rotations and the time taken which shows on the LCD (Liquid-Crystal Display). There was a controller box which made students could set the number of rotations to be counted and also adjusted the speed of rotation of the motor by increasing or decreasing its power. In addition, it demonstrated centripetal force by using springs as aids and loads that added to a rotating box above the propeller. The length of the spring which increased, could be seen using a stroboscope. The practice device be equipped with a student worksheet. Based on the results of the validity of the expert material score was 96.88%, from the expert media score was 93.75% and from the expert learning score was 82.81%. The overall result of the validity test gets excellent interpretation for this developing practice device using magnetic sensor for circular motion.