How to Measure the speed of sound in a laboratory?

Here we will see How to Measure the speed of sound in a laboratory. It is possible to measure wave speed using the equation: speed = distance travelled/time taken

The problem with measuring the speed of sound in air is that sound travels quickly. So we must find a way to measure short times accurately in the laboratory. Figure 1 below shows how we can do it.

• A loudspeaker is connected to a signal generator that produces short pulses of sound.
• Two microphones are placed near the loudspeaker but separated by a short distance, d. Each microphone is connected to an input of a dual-beam oscilloscope.
• The dual-beam oscilloscope can measure the time difference, t, between the sound reaching microphone A and microphone B. (figure 2 below)
• Now we can measure the sound speed using the equation: speed = distance travelled/time taken = d/t