Measuring the Speed of Sound

Student Manual

The objective of this task is to measure the speed of sound using the ‘time of flight’ technique. The apparatus comprises a meter rod, two microphones and a speaker that are connected to the computer’s sound card. This is shown in Figure 1. The microphones are separated by a distance d which can be varied, in steps of 10 cm (say 100 to 10 cm).

Software Code MATLAB codes
Sample Results Time of flight vs. Distance plot
Experiment Code 1.9A
Version 2nd january 2016-2016-v1

Further Readings and References

No references found

Pictorial Procedure


Characteristics of Beverage Bottles as Helmholtz Resonators


It is a common phenomenon to observe that blowing over a glass beverage bottle produces a sound of a fairly definite frequency. The aim of this experiment was to see how well we could approximate glass bottles (such as that of a Sprite bottle) and a round bottom flask as ideal Helmholtz resonators in determining their fundamental frequencies and other associated harmonics. It was seen that though glass bottles are not Ideal Helmholtz Resonators, as they have no defined boundary between their neck and cavity, they can be assigned an average boundary level and then the approximation works to a fair degree of accuracy. In addition, a round bottom flask seems to, and can be approximated to a considerable degree, as an Ideal Helmholtz Resonator.



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