Understanding the Physics BehindConstrained Layer Dampening For

Reducing Acoustic Emissions

First Name, Last NameHomeroom _____

Grade _____

Title Slide

Guidelines to follow for Title Page (Slide #1) DUE ________

□ States the research question clearly and concisely.

□ Shows the student’s name, homeroom and grade level labeled clearly

Purpose

By doing this project, the experimenter is trying to discover how much of a difference there is when a cookie sheet is dampened and struck with a nut. The question is what is the difference in the acoustic emissions when a cookie sheet is struck with a nut when un-dampened and dampened. The experimenter wanted to do this project because he had never really thought about this, so he wanted to learn about dampening and acoustics. It might influence the world by making more people understand the effects of dampening sounds that may be produced too loudly.

Purpose Slide

Guidelines to follow for Purpose (Slide #2) DUE ______□ States precisely what the investigation was attempting

to discover.□ States a definite question or problem. □ Answer how your experiment will influence the world.

What value will it have outside the classroom?□ Explain why you wanted to research this question or

problem.□ State what you hope to learn from this project.□ Written in one complete paragraph.

Hypothesis

The experimenter thinks that the dampened cookie sheet will make much less noise than the un-dampened cookie sheet will. He is not sure how much the difference will be, but he imagines that the difference will be more than half of what the normal cookie sheet will produce. The experimenter has come up with this hypothesis because he knows what it means to dampen the amount of sound an object makes, and, from this prior knowledge, he is pretty sure that it will make a quieter noise.

Hypothesis Slide

Guidelines to follow for Hypothesis (Slide #3) DUE _______

□ A hypothesis statement is present-what do you think is going to happen in your experiment?

□ Explain why you made that particular hypothesis statement. Answer how you arrived at that possible conclusion?

□ Written in one complete paragraph.

Variables• Independent Variable: Dampening layer on

cookie sheet• Dependent Variable: Duration of acoustic

emission heard• Control Group: No dampening• Experimental Group: Full dampening, half

dampening, quarter dampening.• Constants: Area tested, cookie sheet, audio

program, nut size, distance I held the nut from the cookie sheet (1 foot).

Variables Slide

Guidelines for Variables (Slide #4) DUE _______□ Each different type of variable is clearly

labeled□ There is only one variable: being tested

(independent/manipulated); one variable being measured (dependent/responding); one variable as the control

□ There are multiple items under controls and experimental groups

Terms to Know for Variables• Independent variable / manipulating variable: the experimenter changes a

factor to observe what will happen. The factor that is changed is the independent / manipulating variable.

• Dependent variable / responding variable: The factors that were changed may cause something else to happen. The “something else to happen” is the dependent / responding variable. This is what the experimenter measures (be sure to measure in metric units).

• Constants: the factors that stay the same throughout the entire experiment. The experimenter wants to keep everything the same except for the independent variable being tested.

• Control Group/Comparison Group: a study group that is used as comparison. Think of the standard situation. A sample that is treated like the other experimental groups except the independent variable is not applied to it.

• Experimental Groups: Those that have something done to them. The “something” is the independent / manipulating variable.

Materials● Computer (what Audacity will be used on)● Microphone, either internal or external (to record the sound)● Sound-recording software that shows audio traces (Audacity, the program used to

play back all the sounds)● Table or counter top (to put all the materials on, especially vise and computer)● Cookie sheet, 203.2mm or larger (to produce sound when struck)● 1.8288 m string (to hang the nut by)● Tabletop vise (to hold the cookie sheet in place)● Fold-out table (to suspend the nut from)● Steel nut= 12.7 mm (used to strike the cookie sheet)● Ruler (measure the needed distance from the cookie sheet to the nut)● Double-sided carpet tape (to affix the sheets to the cookie sheet)● Thin metal or plastic sheet that is smaller than the cookie sheet that 1-2 large pieces

that can be cut into at least 3 different-sized pieces (used as a dampener)● Tin snips (to cut the metal sheet to the appropriate sizes)● Notebook (to record all the data found in the tests)

Materials SlideGuidelines to follow for Materials (Slide #5 or more) DUE ________□ Apparatus (equipment used) and materials are listed□ Drawings and photographs are present if they enhance and clarify

the apparatus□ List the material used and one sentence explaining how it is being

used in the experiment.□ You may use bullet points where one bullet relates to one piece of

equipment used.□ Be sure to include how much of something is being used for each

trial and how much for the whole experiment (You must have at least four trails).

□ Always use metric units: i.e grams, liters or milliliters, centimeters or millimeters, and °C.

Procedure1. Hook up a microphone to a computer2. Download a computer program for recording (Audacity)3. Using a tabletop vise, hold the cookie sheet vertically above a table or counter top.4. Tie a piece of string around the steel nut. Then, suspend the nut from a chair, folding table, rack, or

other small piece of furniture placed on the same table as the vertical cookie sheet.5. Place the computer and microphone on a table on one side of the cookie sheet. The nut should be

hanging on the same side of the cookie sheet as the computer and microphone.6. Start the recording. Then, use a ruler to measure the distance from the cookie sheet, and release the

nut a foot away from the cookie sheet.7. When I hear no more ringing from the nut striking the cookie sheet, stop the recording.8. Record the wave pattern and duration in a notebook.9. Repeat steps 6-8 about 5 times for multiple trials.10. Cut at least three different sizes of dampers from the thin metal or plastic sheet with the tin snips,

all being smaller than the cookie sheet.*11. Apply the smallest dampening layer to the other side of the cookie sheet (not being hit).12. Use the double-sided carpet tape stick the damping layer to the cookie sheet.13. With the damping layer in place, repeat steps 6-9. Each time I end a trial, I use another sized

dampener.*The three dampeners should be one nearly the same size as the cookie sheet, one half the size of thecookie sheet, and one a fourth of the size of the cookie sheet.

Procedure SlideGuidelines to follow for the Procedure (Slide #6 or

more) DUE ________□ Step-by-step, chronological procedures are present.□ Number of test groups is adequate, and the number of

trials within each test group is adequate. Be sure to state “Repeat steps ___ through ____ three more times.”

□ The control of variables is evident. (Make sure you are testing only one variable!)

□ The procedure should be presented in step-by-step form. Do not leave any step out, even “gathering materials.”

Trial 1 Data TableAmount Dampened Amount of Time it Rang

No Dampening 2 seconds

Full Sheet 1/4th seconds

Half Sheet 1/3rd seconds

Quarter Sheet 1 second

Trial 2 Data TableAmount Dampening Amount of Time it Rung

No Dampening 3 and 1/4th second

Full Sheet 1/8th second

Half Sheet 1/3rd second

Quarter Sheet 1 and ½ second

Trial 3 Data TableAmount Dampening Amount of Time it Rung

No Dampening 3 and ½ seconds

Full Sheet 1/8th second

Half Sheet 1/4th second

Quarter Sheet 1 and 3/4th seconds

Trial 4 Data TableAmount Dampening Amount of Time it Rung

No Dampening 3 seconds

Full Sheet 1/8th second

Half Sheet 1/4th second

Quarter Sheet 1 and 3/4th seconds

Trial 5 Data TableAmount Dampened Amount of Time it Rung

No Dampening 3 and ½ seconds

Full Sheet 1/4th second

Half Sheet 1/3rd seconds

Quarter Sheet 1 and ½ seconds

Averages of Data TablesAmount Dampened Time of How Long it Rung

(in seconds, rounded to the nearest hundredth)

No Dampening 3 seconds

Full Sheet 0.15 seconds

Half Sheet 0.29 seconds

Quarter Sheet 1.5 seconds

Data Table Slides

Guidelines to follow for the Data Tables (Slide #7 through #10) DUE _________

□ Data is organized into tables/charts.□ Data is quantitative and correct units of measurement (metric)

are used and labeled in the table.□ Data is clear and accurate.□ Each trial has its own data table□ There are headings for the columns and rows of the data

tables□ 5 trials are required

Data Graph

Graph SlideGuidelines to follow for Graph of Data (Slide #11) DUE ___________

□ Graph has an appropriate title, labels for each axis with units when necessary, appropriate scales and a key.

□ All students must have at least one graph explaining the results of their experiment. They may choose to do one graph with all of the trials present or a graph of each individual trial.

□ Students may use bar, line or pie graphs to represent their data. Students will decide which one is appropriate to show their data.

□ 1 paragraph explaining what your data is showing you. Explain your data. What trends or patterns did you notice in your data? Is there any data that is out of place? Why is this so? Why did you get the results that you did?

Graph Analysis

The data shows me that the more it is dampened, the less sound the cookie sheet will make. Sometimes, the differences can be a dramatic change in the time the sound is produced. From what I see, no data is out of place. It all seems very logical to me, or anyone else who would look at my results. I think that I got these results because the size of the sheets I put on the cookie sheet. As the sheets got smaller, the time the sound was heard got longer, and when there was no dampening layer, the amount of sound heard was longer. To me, and many others, these results make sense.

Graph Analysis Slide

Guidelines to follow for Analysis of Graph (Slide #12) DUE ___________

□ 1 paragraph explaining what your data is showing you. Explain your data. Think about.. -What trends or patterns did you notice in your data? -Is there any data that is out of place? Why is this so? -Why did you get the results that you did?

Conclusion

My hypothesis was correct because as I applied less dampening layers, the duration of the time I could hear the sound produced. The reason why is because as less dampening is applied, the more sound can be produced from the cookie sheet. All of my research had either helped prove the results or help me understand the concept of acoustic physics. The only problem I encountered in the experiment is the cutting and taping of the aluminum sheet. If I were to perform the experiment again, I would probably either use different metals, different nut size, and/or a different cookie sheet size.

Conclusion SlideGuidelines to follow for this section: Conclusions (Slide #13 or more) DUE _______

Some questions to answer in your conclusion statement. 1) Was the hypothesis statement correct? Why or why not?2) Explain your data. What trends or patterns did you notice in your data? Is there

any data that is out of place? Why is this so? Why did you get the results that you did?

3) How did your research support or disprove your data? What did you learn from your research that helps you answer how and why you got the results that you did? If there was nothing that helped, then what should you research to help with explaining the data?

4) What problems/changes did you encounter in your experiment? How did these problems affect your results? How did you correct these problems?

5) If you were to perform this experiment again, what would you change to make it better and why?

Overall Presentation

Overall Slide Presentation Guidelines: DUE ________-Be as creative as you want in the design of the slides and the

way the information is presented. Add color, add pictures, add creative ways for the information to appear and disappear. MAKE SURE the font on the slide is readable and large enough for the whole room to read.

-When you save your slide presentation, be sure to include your name and project title in the name of the document so it will be easy for Mr. Spencer and Mrs. Weber to separate the presentations into the individual classes. Student must “share” the document with mrs.weber201@gmail.com in Google drive.