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We tested phyphox application with 18 students (age of 17 years) in individual- and pair works at home, in physics class works and in project works. As introductory project, the students have chosen openly an individual- and a pair work from the phyphox menu, depending their smartphone sensors. [1]

To step forward to mechanical damped oscillations, we studied the problem of pendulum and the vertical oscillation in water, as physics class phyphox project in groups of 3-4 students. We used the equation of motion of Newton, supposing a term proportional to velocity of the studied non-conservative system.

Afterwards we searched for electromagnetic waves in a circuit containing a coil with loss and a capacitor (LCR-oscillator circuit). Using Kirchhoff’s voltage law, we can formulate analogous differential equation to the mechanical one, replacing displacement to electrical charge and velocity to current intensity. The LCR-oscillator circuit was charged by direct current, then discharged to create an electromagnetic damped oscillation. [2] [3]

Satisfying some conditions concerning the LCR-oscillator circuit, we could demonstrate the existence of electromagnetic damped oscillations. Using our data we can compare the magnetometer sensors of different types of smartphones and estimate some characteristics of the waves, as its period or circular frequency. Depending the type of smartphones we could pick data by 10-20 ms.

Finally, we have developed an Arduino controlled Hall-sensor, by which we could already pick data by 0.2-0.3 ms. This precision allow to determine more precisely the characteristics of the electromagnetic damped waves and the parameters of LCr-oscillator circuit.

References

[1] phyphox, Physical Phone Experiments, https://phyphox.org/

[2] N Westermann et al , Measuring the magnetic field of a low frequency LC-circuit with phyphox, 2022 Phys. Educ. 57 065024

[3] Feynman, R. P., Leighton, R. B., Sands, M. (1963). The Feynman Lectures on Physics, Addison-Wesley

Contribution categories - primary focus | University |
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Contribution categories - type | Application (shared experience, activity suggestions) |