# Experimental speed of sound

1. May 27, 2010

### momopeaches

1. The problem statement, all variables and given/known data
For my physics lab, we have to calculate the speed of sound through steel and aluminum based on an experiment we did using a microphone and a program called Logger Pro. The resulting graphs gave the frequency of the sound of the aluminum rod as 2109.38 Hz, and the frequency of the sound of the steel rod as 2578 Hz. The aluminum rod is .995m, and steel rod is .987m. We are also told that the wave length is twice the length of the rod.

2. Relevant equations
velocity = wavelength * frequency

3. The attempt at a solution

v(aluminum) = (2*.995)*2109 = 4196.91 m/s
The given value for the speed of sound through aluminum is 5100 m/s, so my experimental value is about 18% off of the actual value. Am I missing something, or is my data just poor?

v(steel) = (2*.987)*2578 = 5088.97 m/s
This value is also very off of the given value, which was 5960 m/s. So for this one, I have about a 15% error. Again, am I using the wrong equation, or is my data just poor?

Note that I did not do the experiment, this was data given to the students by our instructor.

2. May 27, 2010