Welcome to my 7th grade science blog!

Wednesday, March 16, 2011

Rubber Band Sounds


This is the second lab that I'm posting.

Rubber Band Sounds

I.  GUIDING QUESTION: How are the sounds that vibrating rubber brands produce effected by their width, their stretch, their length and how far out they are stretched?


II. HYPOTHESIS:
I think that the more the thinner, more stretched, shorter, or more stretched out to the side a rubber band is, the higher it will sound.


III.  Exploration (PLAN & DO A TEST):

Materials:
  • Thin Rubber Band
  • Thick Rubber Band


Procedure:
  1. Stretch out a rubber band.
  2. Pull and let go off the rubber band, leaving it to vibrate
  3. Repeat steps 1 and 2 using different amounts of stretching, stretching to to the side, or change the length or width of the rubber band.


                                               


IV.  RECORD & ANALYZE:
Amount of Side-StretchObservations
1 centimeterlow, almost no sound
2 centimeters sound is higher and longer than with 1cm
3 centimeterssound is higher and longer than with 2cm
4 centimeterssound is higher and longer than with 3cm
5 centimeterssound is higher and longer than with 4cm

Amount of Length-StretchObservations
Lowa very low, unclear sound
Higha rather high pitch, slightly unclear sound

Thickness of Rubber BandObervations
Thicka very low, very unclear sound
Thina relatively low, unclear sound

Length of Rubber BandObservations
Shorta rather high pitch, clear sound
Mediuma lower pitch and more unclear than the “Short” one
Longthe lowest pitch and unclearest sound of the three




V.  Concept Acquisition (CONCLUSION):  
Our Guiding Question was How are the sounds that vibrating rubber brands produce effected by their width, their stretch, their length and how far out they are stretched?”. To this I answered, “I think that the more the thinner, more stretched, shorter, or more stretched out to the side a rubber band is, the higher it will sound.” I believe that my hypothesis was right as our results clearly show answers that match my expectations. This is probably because when the waves travel through a looser or shorter rubber bands, their frequency and therefore even their “pitch” lowers. For the side stretching part, I believe that we acquired our answers thanks to the larger stretch increasing the amplitude of the waves and therefore making the sound more audible.


VI.  Concept Application (FURTHER INQUIRY):
The stretching of the rubber bands was done by hand so we cannot rely on its accuracy. If we used something more accurate than human labour, we could get more accurate results. I still believe that the general results would remain the same. Also, we could do tests with material other than rubber bands to see if the results would remain the same or if they would change with the change of material. Overall I think that this was a “simple” lab and the general idea seems to be more important than exact results. For exact results, the tests would have to have been conducted differently.

1 comment:

  1. Good job Adrian! It is clear that you understand the sound concepts and how changing certain properties of a rubber band causes change in the sound properties. How do you suppose understanding this would help you in understanding how string instruments work?

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