A $10.0 m$ long PVC pipe is attached to a speaker at one end and it is sealed at the other end. A microphone is placed next to the speaker. The PVC pipe is filled with an unknown gas. The speaker emits a short click and the microphone records the following pattern as a function of time. Note that the data recorded by the microphone does not include the initial loud pulse from the speaker—only the reflections within the pipe are recorded.
Using data obtained from the graph estimate the approximate speed of sound in the unknown gas?