The Wave Simulator

I found the wave simulator quite interesting, and there are a few tests I conducted to see what would happen.

The first test I did was to see how would high frequency affect the features of the wave. I saw that the wavelength of the wave got noticingly shorter, and that there were much more waves, then there were when the frequency was lower. The waves moved much faster, as well. I also saw that the waves on the graph got much faster, and smaller, as the frequency increased.

The wave graph when the frequency is higher.

The wave graph when the frequency is lower.

The  next test I did was to see how waves would react once you put a barrier in. For this test, I put both the amplitude, as well as the frequency at the middle. Once the waves hit the barrier, they came back, creating the illusion that there are much more waves, and that the frequency suddenly got higher. Another thing I noticed is that when some of the waves passed the barrier (because of the gap that was left), their wavelength got much shorter, and the waves spread out. A diffraction occured.                   

For my last test, I did  a similar thing as I did above, except I put the barrier in the middle of the tray. I found that the exactly same things happened. The waves bounced off the barrier, following the Law of Reflection. The waves hit the surface which they could not pass thorugh, and they bounced back. Both the angle of incidence and the angle of reflection were the same. Diffraction also occured.

One more thing I noticed throughout all the test that I did is that the amplitude does not affect the waves' frequency, whasoever. When I made the amplitude really high, and really low, the frequency was still the same. Amplitude didn't affect the wavelength, either. The frequency and the wavlength was the same, when the water drops were small, and when they were really big.

Earthquakes around the world

Today, we were supposed to investigate the earthquakes around the world. The green lines show where eathquakes caused by compression occur. Compression is when the movement of tectonic plates causes the rocks to squeeze until they fold or break. As you can see, the compression earthuakes occur around the Euroasian and Philippine plate. There are also a bit of compression earthquakes around the Arabian plate. The orange/reddish lines represent tension. tension is a force that streches the rock, so that the rock becomes thinner in the middle. Earthquakes that cause tensions usually occur around the African plate, as well as the Indo-Australian plate. There is also a bit of earthquakes that cause tension around the Nazca plate (Pacific Ocean). The last type of stress that occurs due to earthquakes is shearing. Shearing is when the rocks push in two different directions. This can cause the rock to break, slip apart, or change it's shape. The earthquakes that cause shearing are usually cause some damage and are quite dangerous. Shearing does not occur often, and it does not occur in a lot of places. Shearing happens on the Western part of the United States, as well as a very small part of South America. Shearing also occurs in the Indian Ocean, near Australia.
From what I have researched, I can state that tension is the type of stress that occurs the most around the world. I think this because, since tension mostly happens in the Atlantic Ocean, and the Indian Ocean, it affects the lands that have shores on either sides of the oceans. That means that, if an earthquake causing tension happens in the middle of the Atlantic, it is most likely to affect both, Africa, as welll as South America. However, the most devastating earthquakes are the ones that cause compression. I have looked at the data we were given, and some of the most devastating earthquakes have happened around India, and the outline of South America.
Earthqaukes usually occur on tectonic boundaries, or fault lines.

Waves lab report

Waves in various liquids lab

How will the different liquids affect the wavelength and the frequency of the wave?

My hypothesis for this lab is that the frequency will be slower, and the wavelength longer in the liquids that are more dense (honey, for example). I think this, because, in more dense liquids, the waves will need much more energy in order to travel through the packed liquid with a high frequency. However, I cannot give the waves the energy (cannot cause a stronger disturbance) they need in order to travel in high frequency, because I have to keep the experiment fair. I think that the waves will travel much more freely and the frequency will be much higher (wavelength shorter), in liquids with lower density (water).  

In order to conduct this experiment there are different materials I used. They are:

• A tray.
• A plasticine stick to cause the disturbance, and create the waves.
• A ruler, possibly plastic, to measure the wavelength.
• A stopwatch, to help you measure the frequency.

The different mediums to test the waves in:

• Water
• Oil
• Honey
• Yogurt
• Orange juice

There are several steps that I took in order to conduct this experiment. The list of steps is below:

• Pour a few cups of water into the tray.
• Then, cause a disturbance by using a plasticine stick (make sure that you keep the force the same; touch the water with plasticine each second)
• With a ruler, measure the wavelength, and, then, using a stopwatch, measure the frequency of the wave.
• Record the speed, and your observations.
• Repeat these steps each time you use another liquid.

My observations

Water- The waves in this liquid moved more freely, and the water has a low density. The waves spread their energy more easily in the water. The wavelength is 2cm, and the frequency is 1 Hertz.
Oil- The oil has a very high density, but not as high as honey, for example. That is why I have noticed that the waves do move, but they do not reach the end of the tray. In order for them to be able to do that, I would need to apply a higher force, but I can’t change that variable, because I need to keep the experiment fair. This wave travels 7cm, and the frequency is 1 Hertz.
Honey- Honey is a very packed liquid, with a very high density. That is why no waves were produced in honey. The waves didn’t have enough energy to pass through such a dense liquid.
Yogurt-  Like honey, yogurt is a very dense liquid, almost in a solid, jelly-like state. No waves passed through, and that is something I expected from such a dense liquid.
Orange juice- I found that orange juice has a density that is lower then oil, but higher then water. The waves did reach the end of the tray, and the wavelength of the wave was 3cm, while the frequency was 1 Hertz.
Another observation I made was that every liquid that actually had a low enough density to produce waves had the same frequency of the waves. So, water, oil and orange juice have, obviously, different densities, and despite that, the frequency of the waves was the same. I think this was because of the force I applied (one small disturbance, per second). I predicted that, if I used a bigger force, creating a greater disturbance, the frequencies could have been different.


I think that my data and my analysis was quite precise, because I repeated the steps for each liquid several times in order to make sure that it is correct. As I said in my hypothesis, the pattern is that the higher the density, the longer the wavelength is, and, therefore, the slower the speed of the wave is.

My conclusion

My guiding question is How will the different liquids affect the wavelength and the frequency of the wave?. And, at the end of this lab, my answer is that the wavelength depends on the density of the liquid, while the frequency mostly depends on the force that is applied to the liquid, less to the density. The variable that I had to keep the same was the force, and the changing variable were the different liquids. I think that my hypothesis was partly correct, but partly not. Only wavelength depends on the liquid’s density, the frequency has nothing to do with the density, just the force applied.

Further inquiry

I think that this lab is very hard, and that it was quite difficult to be precise, and, therefore, there were quite a few areas for error. Firstly, waves move fast, which means that it is very hard to exactly measure the wavelength. Also, it was very hard to use EXACTLY the same force on all the liquids; that is, cause the equal disturbance. By doing this lab, I have developed a few questions, that I would like to find an answer for during the rest of this unit:
1. How does density affect the speed/wavelength of waves? What molecules, atoms, etc. are involved?
2. Is it possible for really packed liquids to create waves? If so, how?

How do waves react once they hit a surface?

In class, we have conducted an experiment to investigate how would waves react once they hit a surface. We used balls made out of different materials, and of different density to represent the waves. Against a wall, we put a piece of paper, and along we rolled ball after ball, tracing the path it takes once it hits the wall with a marker. All the balls were different density, and were made out of a different material. My partner for this lab was Aca.
 From what we have observed, balls will with different density will come back a different way, and will take a different path. The balls which have a lower density bounce on the wall, and come back on the similar path it was rolled on. As the different balls get more dense, they start going in the opposite angle/ direction from which they were rolled from. As I wrote above, when a wave hits a surface it cannot pass through, it will come back the way it came from.
From this lab I have learnt a lot, since before I have always thought that once a wave bounces into a surface, it will just automatically stop. This experiment helped me rah a conclusion that whn a wave hits a surface or barrier, it will deffinetely come back, but which way, and which speed, depends on the density and the properties of the wave.

The wave experiment

This is the first experiment we did, and this is the first sketch without any barriers. As you can see, we caused waves on two opposite sides of the tray. The waves move quite freely, and they do cross each other's way, and this is called a compression. The two waves compressed together. We tried to create an equal disturbance, to see how would the waves of the same frequency react once they met each other, in the middle of the tray.

This is the second experiment we did, and we caused the waves on the opposite sides of the tray, but they were both on the right. We wanted to see whether the waves would fill the whole tray, or not. Again, we caused an equal disturbance on both sides, and the waves did cross each other, but didn't occupy the whole tray. Our hypothesis was that in order to make the waves travel further, and fill the whole tray, you nees to apply a stornger force, and apply a bigger disturbance.

This is our third, and last experiment without any barriers. To this experiment we applied a little bit more force, and caused a bigger disturbance, and, sure enough, the waves filled the whole tray, with corssing each other, because, as we know, waves will travel in all directions, depending on how strong the force is, and whether there is any force holding the wave back.

This is our first experiment with one barrier. As you can see from the sketch, waves go in all directions, unless there is a force holding it back, and in this case, the force is the barrier that we have put in the middle of the tray. The waves couldn't go past the barrier, so they went through the place they did have. Strangely enough, the waves didn't affect the small patch of water hidden behind the barrier. This part of the tray remained perfectly still.

For this experiment we made the disturbance exactly opposite from each other, and the barrier exactly in the middle of the tray. What we expected to happen did happen. The waves stopped where the barrier was, but went through the two little gaps that they had. Here, they just had a small collison.

This is similar to the experiment we have drawn above, except we have just moved the source of the disturbance and the barrier a little to the left. As you see, the waves had a similar reaction, accept they had quite a big collison over the barrier. The waves couldn't go past the barrier, so they went to the big space above it, and compressed.

This is the first experiment that we did with two barriers, and as you can see, we have just left a small space in the middle of the two barriers for the waves to pass through. The waves stopped at the barriers, and since they didin't have a lot of space in between to pass thorugh, there was just a small collison between the two waves.

For this experiment, we wanted to see how a  wave would react is if it just had a tiny spot to move in. For this experiment, we applied the same force to both sides, to make the disturbances equal. We have realized that the wave that was trapped in a small place had a higher frequency, because it wasn't as spread out as the other wave, which had most of the tray to move, and spread the energy around.

This last experiment was our last one, and we wanted to have some fun with it, so we created this interesting design, where we put one barrier exactly in the middle of the tray, and the other one just a little below. We caused the disturbances righ behind each of the barriers. Of course, as seen in the above example, the wave that was behind the barrier that was closer to it, had a bit higher frequency. Since the waves had quite some space for collison, they did cross over each other just a little bit.

A photo we took during the experiment