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Sunday 27 March 2011

How does the density of a material affect the properties of sound traveling from a tuning fork?



Guiding Question:
How does the density of a material affect the properties of sound traveling from a tuning fork?
Hypothesis: The more dense the surface the lower the pitch
Controlled Variable
Tuning fork- G 384
Force- one medium hit
Manipulated Variable
Object- we are using four different types of materials.
Materials
  • Tuner
  • Notebook
  • Glass
  • Wood
  • Aluminum
  • Locker material

Tuner – G-348
Surface
Pitch Loudness
Aluminum
2800 kg/m3
Aluminum is the densest material that we tested. What we observed is that Aluminum produced the softest sound.
Glass
2500 kg/m3
Glass was a lot louder that aluminum was, it had an annoying sound. While Blaise was listening to it, I could hear it clearly about 1/2 meter away from the glass.
Wood (oak)
600 kg/m3
Wood was a lot louder, than both aluminium and the Glass, although it had a softer sound than the Locker.
Locker (steel)
222.260
The locker was the loudest, and least dense from all the materials above. While Blaise was listening to the locker, i stood about 2 meters away from the locker and could hear it.


Conclusion
What I conclude from this lab/experiment, is that the less dense the material, the louder the sound is. It turns out the hypothesis I had was incorrect in the end. What I have learned from this lab, is that the less dense a material is, the louder the sound will be once heard with a tuning fork's vibration.
If I were to do this experiment again, I would probably have used more materials, such as a phone, laptop, or a toilet seat. I would find that pretty interesting, although only if i wouldn't have to put my head on the toilet seat (disgusting.)

Guiding Question:
How does the density of a material affect the properties of sound traveling from a tuning fork?
Hypothesis: The more dense the surface the lower the pitch
Controlled Variable
Tuning fork- B 480
Force- one medium hit
Manipulated Variable
Object- we are using four different types of materials.

Tuner – B-480
Surface
Pitch Loudness
Aluminum
2800 kg/m3
Aluminum is the densest material that we tested. What we observed is that Aluminum produced the softest sound.
Glass
2500 kg/m3
Glass was a lot louder that aluminum was, again. While it also had a very intense sound.
Wood (oak)
600 kg/m3
Wood was a lot louder, than both aluminium and the Glass, and had an intense ringing.
Locker (steel)
222.260
Surprisingly this material was way louder than any of the other materials, even with a shorter tuner it was a very loud and intense pitch and sound.

Conclusion:
Next to the first lab Blaise and I completed, this was the probably the same. In this lab we used a different tuner; we used one high, and one shorter tuner. Blaise and I wanted to check if the results of the two different tuners would be identical, or completely different, or in the middle. What we found out is that the two tuners made almost identical sounds. What we found out is that with both tuners, the less dense the material was, the louder the sound was.
Further Inquiry:
If I were to redo either, or both of these tests, I would, as mentioned in the first conclusion, that I would attempt to use a locker, a phone, and/or a toilet seat. I would use these materials because I think they would make a different sound. Al-in-all, I think I worked pretty well on this project, and that me and my partner (Blaise) did a pretty good job together!



Tuesday 15 March 2011

Notes on Bill Nye Sounds Video

  • Sound is tiny vibrations in the air
  • Oscilloscope- makes sound waves visible
  • The ear is like a funnel that helps sound go into the eardrums
  • Sound travels faster through metal and brick faster than through air
  • Sound travels 18 times faster through metal than air
  • An echo happens when sound bounces off something
  • When sound enters the ear canal it becomes smaller
  • Higher frequency = Higher pitch
  • Lower frequency = Lower pitch

Friday 11 March 2011

Properties of Sound Lab

Purpose:

To determine how changing amplitude and frequency can change how a sound is perceived.

Procedure:

Experiment #1: Amplitude

1. Have 2 partners each hold one end of the thicker rubber band and pull until the rubber band is taut (not loose).

2. Pull the rubber band about 1 cm away from the middle. Let it go. How far does the band move? Describe the sound you hear in a table.

3. Repeat step 2 four more times. Each time, pull the band back further. Describe how the sound changes each time in the chart below.

Experiment #2: Frequency

1. Have 2 partners each hold one end of the thicker rubber band and pull until the rubber band is taut (not loose).

2. Pull the rubber band about 2 cm away from the middle. Let it go. Observe the sound.

3. Repeat steps 1-2 with the thin rubber band and describe the difference in the chart below.

4. Now, take the thicker rubber band again. Repeat steps 1-2.

5. Now pull the thicker rubber band a little bit tighter and repeat steps 1-2. Observe how the sound changes.

6. Pull the rubber band even tighter and repeat steps 1-2. Observe how the sound changes. Record your observations in the chart.

7. Last experiment: have two partners hold the thick rubber band just like in step 1. Repeat step 2 and observe the sound.

8. Now, have one of your partners move his or her hand so that the rubber band is a little bit shorter. Repeat step 2 and observe the change in the sound.

9. Repeat step 8 two more times, making the rubber band a little shorter each time. Record your observations of the change in sound.

Experiment #1

Experiment #2


CONCLUSION:

1. How did the sound change when you changed the amplitude (how far the rubber band was away from the middle point)?

The farther away you pulled it, the louder and sharper the sound became.

2. What happened when you changed the thickness, length, and tightness of the rubber band?

Thickness: the thicker the band is, the duller the sound

Tightness: the tighter the band is, the higher the pitch

Length: the shorter the band is, the higher the pitch

3. Sally is playing the guitar and notices that one of her strings is flat (pitch is too low). What can she do to fix this?

She can tighten the string, which will make the pitch higher.