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