Sound Labs

(20 points each)

  Name:_________________________________            Date:_____________                Period:________

For each lab, on a separate sheet of notebook paper:

1 Write out your procedure.  Include all steps and all tools or instruments used.  Include hypothesis if required in directions.
2 Compile data in a data table.  You may use the sample tables below, but you must copy them into your lab report.  Show all necessary calculations.
3 Create chart as required.
4 State conclusion(s).

1.         Tuning Forks

Get any 3 different tuning forks.  The frequency is stamped on each.  Make sure you have different pitches.  These should be struck on your shoe.  If you strike them on ANY hard surface, you will not be permitted to complete this lab.

  A B 34400/A Relative Pitch
Tuning Fork Note Frequency (Hz) Length of Prongs (cm) Wavelength (cm) 1 (lowest) - 3 (highest)
         
         
         

Create a chart of this data and use the chart to predict the frequency of the unknown fork.

Compute your percentage error once given the instructor's value.

2.        Pipes

Get the set of three gray pipes.  Blow across one end of the pipe while holding your finger over the other end to generate a tone.  Complete the table below.  Compute the frequency of each pipe

  A B B/A Relative Pitch

Highest/Middle/Lowest
Pipe Wavelength=4 x pipe length (cm) Speed of Sound (cm/s) Frequency
Shortest   34400    
Middle   34400    
Longest   34400    

Create a chart of this data and use the chart to predict the frequency of a 30 cm pipe.

Compute the actual frequency for a 30 cm pipe and compute you percentage error.

 

 

3.        Resonance

           In this activity you will find the length of a column of air which vibrates with a given sound frequency.

           Use a beaker full of water and a pipe.  Work with a partner.  Move the pipe up and down in the water until you hear the pipe resonate with the tuning fork.  Have your partner measure the height of the pipe above the water.  You should run and average 3 trials.  You should test 3 tuning forks.

Create a chart of this data and use the chart to predict the pipe length for the unknown fork.

Compute your percentage error once given the instructor's value.