Lab Report- Create Our Own One

Lab Report

Despina Katsirouba

7A Science

Mrs. Medenica

June 4^th 2012

Guiding Question: Which of the rubber bands with different thicknesses and diameters of the caps make the strongest, loudest sound?

Hypothesis: The thickest rubber band that is stretched the most will also make the loudest sound.

Variables:  

• Controlled: strength of the pull, sizes of the rubber bands
• Manipulated: stretching of the rubber bands
• Responding: different sounds the rubber bands create

Materials: rubber bands (of three different thicknesses), caps of jars with different diameters, ruler, iphone to measure the VU

Procedure:

First you have to measure the diameters of the caps and the thicknesses of the rubber bands. Then you put the rubber bands around the caps and pull them to create a sound. Then see which rubber band on which jar makes the loudest sound.

Diameters of caps:

1. 12 cm
2. 10 cm
3. 9.5 cm

Thicknesses of the rubber bands:

1. 0.5 cm
2. 0.3 cm
3. 0.2 cm

Recordings (in volume units):

Rubber Band 1:

• Cap 1: 10 VU
• Cap 2: 7 VU
• Cap 3: 15 VU

Rubber Band 2:

• Cap 1: 15 VU
• Cap 2: 7 VU
• Cap 3: 15 VU

Rubber Band 3:

• Cap 1: 7 VU
• Cap 2: 10 VU
• Cap 3: 18 VU

Data Table/s (This is as far as you will get until you complete the table, but you MUST know what data you will collect BEFORE you begin)  

Graphs:

Data Analysis: The thinnest rubber band on the smallest cap makes the loudest sound, 18 VU. A pattern that I recognized on rubber bands one and two on the second cap is that they both make 6.5 VU. The same rubber bands make the same VU, 14.5, on cap three. I don’t think our data was very precise since the i-phone source was not very good so the numbers that are sown in the graph may not be the exact ones but very close.

Conclusion: Which of the rubber bands with different thicknesses and diameters of the caps make the strongest, loudest sound? The thinnest rubber band placed around the smallest one. Our answer to your guiding question was not even close to out hypothesis since we said the opposite; that the thickest rubber band will make the loudest noise around the bigger cap. The i-phone application that we used was not very precise but if we had used a special tool that probably Dr. G has. Since we had to create our own lab I think the application was enough. In my opinion, our hypothesis was based on our basic knowledge of sound waves, since it is thick so it would probably make the thickest sound just like the guitar.

Further Inquiry: The application that we used on the i-phone to measure the VU was not very accurate so the number had to be rounded so not very precise. Although we went to a quiet room where there was no one there so no sound occured but again it was not as precise as we expected it to be. We could have used a tool that probably Dr. G has to measure it more precisely. Next time we would try to find another way of measuring. Also we could use caps with more difference between them so the results would be higher in difference and try it many times so it can be more precise. The reasons our results came out really close to each other is because there wasn’t much difference between the caps, the application was not very precise and the thickness of the rubber bands wasn’t much. I don’t think we would change the hypothesis or inquiries if we had a different tool.