The smartphone as a barometer in Physics experiments

This paper presents two experiments that take advantage of smartphones pressure sensor, using it to determine the value of the pressure within in equilibrium water in a test tube. In a first experiment, aimed at students of secondary and higher levels, the data collected with the pressure sensor of a smartphone at different depths allow a linear fit, thus checking the validity of Stevin's Law. In addition, based on this law and the parameters of the adjustment it has been possible to determine the density of the water. The density values obtained indirectly by this procedure differ between 2% and 4% of the result of dividing the mass and volume of a sample. In a second experiment, more focused on students of the first university courses of Physics subjects, the submerged smartphone oscillates suspended from a spring. The measurements of the pressure sensor allow, through Stevin's Law, to obtain the time series of the pressure in the corresponding damped oscillation, whose parameters are determined by a non-linear adjustment. The comparison of the free pulsation obtained from these values differs by 1.5% from that obtained from the direct measurement of the period outside the water. In both cases, the results obtained indicate the suitability of the current methodology in teaching contexts