Alfie Norris

7A

29/5/2012

Science

Mrs. Medenica

Decibels Lab

Guiding Question: How does the amount of water in a bottle affect the number of decibels that are emitted when it’s tapped with a spoon?

Hypothesis (Alfie): I think the more water there will be the more decibals there will be because the water has less area to bounce around and lose it’s energy.

Hypothesis (Francesca): The less amount of water the more decibels.

Procedure:

1. Get together all of the materials for the lab.
2. Fill up the bottle with the desired amount of water.
3. Hit the bottle with a metal spoon.
4. Record the amount of decibels and put the data into the a table.
5. Make a graph out of the data table

Materials:

• Bottle with measures
• Alfie’s IPod
• Microphone
• Metal spoon
• Water

Variables:

• Amount of water   

Data Collection:

	Try 1	Try 2	Try 3	Average
100 ml	44.9	44.7	44.5	44.7
200 ml	43.8	43.8	45.7	44.4
300 ml	44.9	44.4	43.3	44.2
400 ml	42.2	43.9	42.2	42.7
500 ml	43.4	42.5	42.8	42.5

Data Analysis:

According to the data that Francesca and I collected the more water there is inside the jug, the less sound is emitted, which, naturally contradicts my Hypothesis as usual. I think this is because sound can’t travel through water so the less water there is the the more amplified the sound will be. I believe that our data is pretty accurate because my iPod Touch was always in exactly in the same spot and I always hit the glass with precision and using the same amount of force, and even if there was a mistake it would show because it would disrupt the trend.

Conclusion

In conclusion I think our data was accurate enough to see a pattern, Francesca and I worked together really well, although in some cases we were... distracted. Even though this lab proved my Hypothesis incorrect I think I have come to understand what and why it was wrong, and what the right answer is.

Further Inquiry

If I were to repeat this lab I think I would include a control which would be no water, just to see what would happen. One thing that would be interesting to learn is how different substances such as jelly or vinegar amplify sound. Or even hard-ish things like soil or moss or even plastic. One other change that I would make if I were to repeat this lab would be to use a different container, so instead of using glass, I would use plastic.