Resumen de Studying Temperature-Dependent Sound Speed in a Constantly Filling Beaker Using a Smartphone

Mamatha Ramanjineyulu Maddur, Arnab Bhattacharya, Praveen Pathak

• Almost anyone who regularly fills a bucket is well aware that the frequency of the sound changes as the bucket fills, and intuitively uses this to shut the tap at the right time. The astute listener also knows that there is a subtle difference in the frequency response depending on whether hot or cold water is filling the bucket. The authors, experienced practitioners in the art of filling a bucket, use a modern variant of such a setup (see Fig. 1) to perform some delightful experiments monitored using a smartphone. To determine the frequency and see the harmonics present, the easiest method is to place a smartphone next to the “bucket” (without getting it wet!) and perform a resonance tube experiment. We also show the variation of the speed of sound as the air becomes warmer.