Measuring the speed of sound

In this experiment the speed of sound was measured through time of flight method using a sound card. Two microphones were placed a distance d apart, a ‘Pluck’ sound was then played from the computer and the signals received at each microphone were analyzed. The time delay between their initiation, which corresponded to the time taken for the sound to travel the distance was noted. The distance was varied with ten sets of readings taken at each distance to minimize uncertainty. The speed of sound was hence calculated by plotting a graph of ‘time delay’ vs ‘distance’ and taking its gradient. The recording, analysis and computation of data were all performed in MATLAB, the code for which was written by the students themselves.

This work has also resulted in a Task numbered 1.9 A for the Physics 100 course.