This work presents a low cost experiment of standing waves on a string. It uses the smartphone app for Android operating system, the “PA Tone”, that generates a sinusoidal signal instead of the expensive commercial hardware. An oscilloscope was used to analyze the sine wave generated from the application to check if there was any change in the waveform with increasing frequency. We also used an oscilloscope to check the reliability of the frequency values indicated at the application settings. The signals generator “PA Tone” was then used with a mechanical oscillator attached to a string, in the classical experiment of creating standing waves, from which the linear density of the string can be inferred. This experiment showed that the smartphone app “PA Tone” is a viable alternative to the commercial signal generators.
standing waves on a string; low cost physics experiment; physics with computers; signal simulator
