Sound Unit Intro Lab

Goal: 
To orient ourselves with the lab equipment and determine the experimental value of the frequencies of different tuning forks.

Background Information:
Sound waves are the vibration of air molecules that originate at a vibrating source, such as our sound box. The vibrations create high and low pressure regions that can be detected by the human ear (within a certain range). Tuning forks are unique from most sound-making objects in that they produce just one frequency while other objects like a guitar produce a combination of multiple frequencies. Two factors that impact the pitch of the sound wave are frequency and period.

Frequency = 1/Period
Period = 1/Frequency

Process: 
In this lab, we used Logger Pro to graph the sinusoidal wave of the sound wave. Using this graph, we were able to measure the period of the function. With this information, and the equations above, we determined the experimental value of the frequency of the tuning fork and compare it to the value written on the fork.

Data:

Experimental Period: 0.002654 s

Accepted Frequency (written on fork): 384 1/s

Accepted Period: 1/384 = 0.0026041667 s

Experimental Frequency: 1/0.002654 = 376.7897513 1/s

Percentage Error: 1.88% 

Experimental Period: 0.002440 s

Accepted Frequency: 426.7 1/s

Accepted Period: 0.00234357 s

Experimental Frequency: 1/0.002440 = 409.8260656 1/s

Percentage Error: 3.95%

Experimental Period: 0.007920 s

Accepted Frequency: 128 1/s

Accepted Period: 0.0035714286 s

Experimental Frequency: 1/0.007920 = 126.2626263 1/s

Percentage Error: 1.36%

Conclusion:
With this lab, we learned to use the equations that we learned in class. The lab allowed us to gain a better understanding of the relationship between period, frequency and pitch.