A sound pulse is detected by two microphones. A fixed electronic delay is added to each measured time. The table shows the results.
| Microphone separation in m\mathrm{m}m | Measured time in ms\mathrm{ms}ms |
|---|---|
| 0.68 | 2.5 |
| 1.36 | 4.5 |
What is the speed of sound after allowing for the fixed delay?
302 m/s302\ \mathrm{m/s}302 m/s
272 m/s272\ \mathrm{m/s}272 m/s
340 m/s340\ \mathrm{m/s}340 m/s
680 m/s680\ \mathrm{m/s}680 m/s