Tuning Fork and Palm Pipe Lab

Big Questions:

How can we tell something (like sound) is a wave if it is invisible or too small for us to see?

How do musical instruments work?

What's the difference between a woodwind & a stringed instrument?

     In this lab, the class examined sound waves using a tuning fork and palm pipes. We were presented with two different sizes of tuning forks. When instructed, we struck the fork onto a firm surface, such as the heel of a shoe, and measured the different sound waves it produced. 
     A microphone attached to a LabQuest device recorded the sound waves and analyzed the different frequencies (in Hz) into a bar graph. The "peak wave" or the longest bar on the graph can be noted as the fundamental frequency. The fundamental frequency is the frequency that humans can hear the best. Other peaks in evenly spaced increments can also be known as harmonics. 
   With the Wolfram Alpha app on the Ipad, the peak frequency was translated into a specific note for each different tuning fork.

In the second part of this lab, we analyzed palm pipes and their relationship to sound waves. We were given pipes of varying lengths in order to discover the specific notes each one would play. By measuring the length and diameter of the pipe (in cm), my class could use the equation: L=1/4(wavelength) -1/4(Diameter inside) in order to solve for the wavelength. 

Ex: Length=0.092 meters

     Diameter=0.015 meters

0.092m= 1/4(wavelength)-1/4(0.015m)

0.368=(wavelength)-0.00375

wavelength= 0.37175 m

After finding the wavelength, we had to solve for the frequency with this equation: (velocity = frequency x wavelength) note: the constant speed in air is 343m/s

343 m/s= frequency (0.37175)        *remember we got the wavelength from the previous equation

frequency= 922.66 Hz

After finding the frequency, we input this data into Wolfram Alpha once more. 

Ex: 922.66 Hz= B flat note

  Each pipe of a different length had a different frequency and would make a different note. With the instruction from our teacher and a sheet of music, we reproduced the cliche song, "Twinkle Twinkle Little Star."

   A video about tuning forks and their relationship to instruments.