Sándor Egri, Hungary, University of Debrecen, Institute of Physics, egris@science.unideb.hu

1. Exciting Physics With Android Devices • An effective measuring system in your hands: • Sensors embedded in mobile phones or tablets • Measuring program (Java andAndroid SDK) Methodology: Active Learning, Inquiry Based Classes Measure Guided Inquiry Method Ask questions Analyze your data Discuss and others, like proximity, GPS … The quickest way of learning something is doing it. Dumping oscillations of a cart. • Other possibilities for physics • Creation of electric signals (audio output) • Detection of sound (audio input, microphone) • Camera, image processing Rotation of a disc in a vertical plane : experiment at home High frequency Measured data (hollow circles) fit well with results of calculation (solid line) Sándor Egri, Hungary, University of Debrecen, Institute of Physics, egris@science.unideb.hu Calibration of the sensor: g=9,81m/2 precise value for Hungary Low frequency and pendulum Mobile is lying on a horizontal plane, Number of data: 600 Display is facing up: a_z=9,781, SD_avg=0,003 (m/s2) Display is facing down: a_z=9.639, SD_avg=0,004 (m/s2) Absolute Mean value: 9,735 (m/s2), SD=0,005 (m/s2) Relative error: 0,8% Quick stretching of the legs. Acceleration: up Standing with mobile in the hand, legs are bent. Measured acceleration = g Braking the fall. Acceleration sensor example Jumping with mobile phone Measured acceleration is proportional with the net force (withoutgravity) acting on the device. A simplified working principle Freefall, measured acceleration =0 m/s2 Range: -20 m/s2 - +20 m/s2 Resolution: 0,04 m/s2 Accuracy::Maximum error app.. 0,3m/s2 SD=0.07 m/s2