Mohammad Jazaa – Theorist
Cory Owens – Recorder
Eduardo Pelallo – Operator
The speed of sound can be determined by measuring the time required for sound to travel through a measured distance and using rate = distance/time. The speed of sound v depends slightly on temperature and given by
where T is in degrees Celsius and v is in m/s.
We used a stopwatch and a pair of wooden blocks outside to time how long it takes for an echo to reach us. We also used two microphones and LoggerPro to time determine the time for sound to travel a short distance.
Calculated Speed of Sound: 472.22
Expected Speed of Sound: 332.6
Percent Error: 42%
Calculated Speed of Sound: 568.1818181818182
Expected Speed of Sound: 332.57
Percent Error: 70%
The above data shows a considerable amount of error (42% and 70%). On the stopwatch trial, this is to be expected, as with delays in human reaction time and the inaccuracy of human senses, trying to listen for an echo over the original sound. On the microphone trial, the percent error can be explained by the slight variance in distance from the first microphone when the sound is created, and possibly the background noise making it difficult to identify the correct “peak” for measurement.
How sensitive is this experiment to the measurement of time? If your errors were large, how much would your time measurements need to be different to reduce them?
This experiment is largely affected by errors in time measurement. For example, in the outdoor trial, a time measurement error of only 0.09s results in a 42% error.
Are these differences achievable in either of the two methods in this lab? Comment and explain.
This is longer the time it takes for an human to react and hit a button, so it is not achievable in the stopwatch trial.
Is there a benefit to using larger measured distances? Explain.
The longer the distance, the less these time differences affect the percent error