Speed of Sound

In this lab we want to see how long it takes sound to travel down and back in a tube, determine the speed of that sound, and compare the average of that value to the speed of sound in air. The temperature in the room is 21.8 degrees C, which means that the speed of sound should be 344.5. The value that we obtained for the closed tube was averaged at .00609, which accounts for a speed of 328.4 m/s which is pretty close to the accepted value (5% change). The open ended tube averaged to be 289.85 m/s which is ~15% off from the anticipated value. We can see that the closed tube had faster travel time than the open tube. Ultimately we were able to record how long the sound took to travel in the tube, determine the speed of sound, and compare it to the expected value.

Objective:
The objective of this experiment is to measure how long it takes sound to travel down and back in a long tube, determine the speed of sound, and compare the speed of sound in air to the value that’s accepted.

Procedures:
First, start by connecting the Vernier Microphone to channel 1 of the interface. Then, use a thermometer to measure the temperature of the classroom and record this value. Now, open file “33 Speed of Sound” and there will be a graph of sound level vs. time. Close one end of the tube and record the length of the tube. Set the microphone as close to the end of the long tube as you can, and have it positioned so that it can detect the initial sound and the echo coming back down from the tube. Then, click on Collect to begin the data collection, and click the dog training device towards the opening of the tube. Click the examine button and determine the time interval between the start of the first vibration and the start of the echo vibration and record this value. Repeat this for 5 trials and determine the average time interval. Then, repeat the experiment for 5 more trials, except don’t close one end of the tube.

Data Analysis:
Vsound = (331.3 + 0.607 * Temp), So the Vsound of the Classroom is (331.3 + 0.607 * 21.8 ) = 344.5326 m/s (accepted value)
We can see from our collected values that the speeds we collected from the experiments were: 328.4 m/s and 289.9 m/s.

Discussion:
As we can see from the data analysis, the velocity of sound with our room temperature should have been at 344.5326 m/s. The value that we obtained for the closed tube is 328.4 m/s, which is within 95% of the expected value. The value for the open tube was 289.9 m/s, which is within 84% of the expected value. We can also see that the closed tube has a faster speed of sound than the open tube. There were some errors in the lab that could definitely account for error in this lab, such as interfering noises, not holding the microphone completely steady, etc. However, I believe that our values were pretty good and close to the expected values with the given circumstances.

Conclusion:
To conclude, my group was able to meet the objective, which was to see how long it takes for sound to travel down and back in a tube, determine the speed of sound, and we were able to compare the speed of sound in air to the value that we determined to be accepted with our classroom temperature.