Thursday, June 7, 2012

Lab Report: Various types of springs

Guiding Question: How does the material a spring is made of and size affect the way the wave moves?  Do longitudinal waves always travel the same way?  What affects the compressions and rarefactions most?  

Hypothesis: It will affect how large and long the compression will be inside the slinky when pulled on. We think that longitudinal waves do not travel the same way but will produce many different patterns. The thing that affects the compression and rarefaction is how much coils you pull back before you let it go and see the compression travel throughout the slinky

Variables:  
  • Control:  length of the slinky (2 meters)
  • Manipulated (What you will change): material and size of slinky
  • Responding (What response you are looking for): How many compressions are made and how they react.

Materials:
  • Slinkys (plastic and metal-34 coils)
  • Meter stick.
  • Camera (To film or take pictures of the compression inside the slinky)

Procedure:

1. stretch the metal slinky 1 meters
2. Gather 5 coils and release them.
3. Observe the number of compressions that it makes and how the energy moves through the slinky.
4.  Gather10 coils and release them.
5. Observe the number of compressions that it makes and how the energy moves through the slinky.
6. Gather 20 coils and release them.
7. Observe the number of compressions that it makes and how the energy moves through the slinky.
8. Enter all data into the table.




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)  

Table 1:  5 coils pulled back
SpringNumber of times the compression hits the ends and reflects back
Flat surface
Metal spring4 times
Plastic spring3 times
metal and plastic combinedpull medal first:1 pull plastic first: 1 1/2


Table 2:  10 coils pulled back
SpringNumber of times the compression hits the ends and reflects back
Flat surface
Metal spring6 times
Plastic spring3 times
metal and plastic combinedpull metal first: 1 times pull plastic first: 1 1/2


Table 3:  20 coils pulled back
SpringNumber of times the compression hits the ends and reflects back
Flat surface
Metal spring10 times
Plastic spring5 times
metal and plastic combinedpull metal first:1 pull plastic first: 2




Data Analysis:
Matia:Chris and I observed really closely and what we noticed was that the metal slinky was more elastic, therefore had more compression to produce and it lasted longer. But then when we combined them together (metal and plastic) for the final test, the results turn out that the plastic had been better and that the compression bounced off more times then the metal one. I’m not sure why this is though.

Chris: I noticed that the metal slinky was much more reflective than the plastic slinky, but when we put them together the plastic slinky was better. There was a difference between plastic and metal slinky depending on which one we started with. If we started with the plastic slinky, the wave went all the way through, but when we started with the metal spring it did not work that well.   

Conclusion:
Chris: How does the material a spring is made of and size affect the way the wave moves? The metal slinky was much more elastic and made more compression to make it last longer than plastic slinky. The amplitude in the metal slinky had a bigger amplitude than the plastic slinky.  Yes they travelled the same way every time we did it. Every time the waves reached the end they reflected back and so on. Compression get affected by how many coils we are pulling back. The  rarefaction gets affected by how big the compression is.Our prediction was partially correct. We said that longitudinal waves would have different pattern, but I did not see anything different from test to test. The other predictions we had were right.
Matija: The material of the slinky affects the compression and the motion of the wave because some materials make the compression stop because they aren’t as elastic as others, so when the compression hits the sides it doesn’t really bounce off but lightly fades away. Yes the longitudinal waves only have one pattern which Chris and I noticed and that's having the compression go from left to right (or right to left) and then reflecting back. The thing that affected compression was the amount of coils we pulled back and then let go. And the bigger/longer the compression the more rarefaction is noticed. Our hypothesis was mostly correct with just a few erros such as the one that we said that we thought there would be more then one pattern in a longitude wave.
Further Inquiry:
Chris: It was a great experiment and the slinkys worked really well. The only thing that was a little annoying was when we put the metal and plastic slinky together, because they would not really hang on to each other.   
Matija: The whole experiment turned out to be great with only minor problems with clipping on the plastic and metal slinky together to see how long the compression would last. I have to say the results of that really stunned me i thought that it would have been more.

1 comment:

  1. Overall, a good lab report. Such a simple test gave you results that you could see. The bigger the disturbance, the more compressions you saw. Therefore, the more energy traveled through the springs.

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