What are the three types of stress in a rock?

The three types of stress in a rock are tension, compression and shearing.

Tension: Pulls crust, stretching it so that it becomes thinner in the middle. The plates are going opposite directions.

Compression: Squeezes rock until it folds or breaks. The plates are moving against each other.

Shearing: Stress that pushes a mass of rock in two opposite directions.

How does tension change the shape of the Earth’s crust?

Tension pulls the crust in two different directions. This makes it cover more area but become thinner. It’s like a rubber band, if you stretch it, it becomes a lot longer. However, it also becomes a lot thinner and weaker. Tension is caused by two plates moving away from each other.

Compare the way that compression affects the crust to the way that tension affects the crust.

Compression pushes the plates together. This makes the plates take up less space, but take u more volume. Imagine that you had a piece of play dough. Compression would be if you pushed the dough together, creating a fat blob. Tension, however, would be the opposite. Tension is when the plates move away from each other. Using play dough, this would be stretching it out and pulling it from opposite directions. The stretched out dough is going to cover up a lot more space than the fat blob dough, but the fat blob dough is going to be a lot thicker and denser than the stretched out dough.

What is a fault?

A fault is a break in the rock of the crust where rock surfaces slip past each other

Why do faults often occur along plate boundaries?

Most faults occur along the plate boundaries, where the forces of plate motion push or pull the crust so much that the crust breaks.

What type of fault is made when plates diverge, or pull apart? What type of a fault is formed when plates are pushed together?

When compression is occurring, or when plates are pushed together, a reverse fault is formed. In a reverse fault the hanging wall is sliding above the footwall. When tension is occurring, or when plates are pulled apart, a normal fault id formed. In a normal fault the hanging wall is sliding underneath the footwall, and the footwall is above the hanging wall and is sliding upwards.

Name five kinds of landforms caused by plate’s movement.

Types of landforms: Mountains, valleys, volcanoes, plateaus, cliffs, and tsunami.

What are three landforms produced by compression in the crust? What landform is produced by tension?

Compression: mountains, volcanoes, tsunami

Tension: rift valleys, volcanoes, seafloor spreading

Where do the major earthquakes occur?

After analyzing the data below I have found out that the major earthquakes happen mostly in the areas of compression. On the map I found 8 areas of compression, 6 areas of tension, and 3 areas of shearing. The main earthquakes, the 9.5 earthquake in Chile and the 9.2 earthquake in Alaska were also in areas of compression.

Wave Simulator

The more amplitude the larger the wave is, and the higher it is from the ground. The more frequency the wave has, the more waves are produced, and the faster they are.

When a barrier is added the waves bounce back, and interfere with the coming waves, creating a less constant movement in the water. This also creates ripples and waves going opposite directions in the tub. On the other side of the barrier only the small waves that pass through enter, making very small ripples and small waves.

Depending on where you locate your barrier the waves are going to interfere with each other, creating ripples. Above the barrier is located almost at the source of the waves (the tap), and observing it it looks almost as if it doesn't do anything, and as if the waves just pass through.


http://phet.colorado.edu/en/simulation/wave-interference

Waves Lab

Guiding Question: Does the weight or the surface area of an object make the largest waves if the object is moved vertically up and down at a constant speed?

Hypothesis: The heavier materials are going to make the balls move faster to the sides of the tub, since are heavier and cause a greater water disturbance and produce bigger waves. The surface area isn’t going to impact anything,

Materials:
4 ping pong balls
Marker with circle base
Small water bottle
Clay barrier
Tub
Water
Timer

Procedure:
1.) Fill a 40*32 cm tub halfway with water. This should be about 4 large cups.
2.) Put your marker hovering up in the air about 2 cm above water surface, in the middle of the tub. Put four ping pong balls around the tip of the marker closest to the water. They should be in a square shape. Then, find a consistent speed and move the marker up and down. Time how much time it takes for all of the ping pong balls to reach the sides of the tub. Make three trials.
3.) Do the same thing, only now using the clay barrier instead of the marker. Notice how the ping pong balls move differently, and mke three trials.
4.) Now, use the small water bottle and make waves. Be very careful- don’t let it touch the bottom of the tub. Make three trials and observe.
5.) Now, find the mean of the three trials for each material.

Data:

	Marker	Clay Barrier	Small water bottle
Trial 1	17.1	9.1	3.8
Trial 2	20.2	5.3	6.1
Trial 3	16.4	8.6	3.1
Mean/Average	17.9	7.666(...)	4.333(...)

Data Analysis:
Looking at my data I can clearly see that the marker took the longest to make all the ping pong balls to touch the sides of the tub, then the clay barrier and lastly the small water bottle. Something I noticed while doing the lab was that if I made the marker, barrier, or water bottle move in an up and down motion so that they touched the bottom of the tub they would alter the path of the ball. This is probably because there are waves going on at the bottom of the tub too, and the waves intercept with the ones from the surface of the water. There are no major outliers in my data, only possibly that the first trial with the water bottle took 6.1 seconds, while the second trial with the clay barrier only took 5.3 seconds. In this case the clay barrier made the ping pong balls move faster than the water bottle. This might have been because of inconsistent speed, or that the speed of the two different trials were different. However, in the mean there was no sign of the clay barrier causing faster movement in the ping pong balls. This indicates that the other trials were more correct, and that we need three trials to make correct assumptions. Something else I noticed was that the mean of the clay barrier and the water bottle were a lot closer than the marker. This doesn’t really make logical sense, since the marker and the clay barrier are closer in size (surface area) than the water bottle, they have more of the same surface area than the clay barrier and the water bottle. Maybe this is because of the outlier of before, of maybe it is because the properties in the marker and the clay is different than the water bottle.

Conclusion:
I think that this was a very interesting lab, and all the waves that go on everywhere are just amazing. It was especially fun since we could make our own lab, so everyone came up with different conclusions about different things in the areas that interested them the most. I found my lab interesting since I found out that the bigger the surface area or amount of space something making the waves takes up, the stronger the waves are. My hypothesis wasn’t correct, since its the surface area that affects how big the waves are, or at least more than the weight. However, in a way it was correct, since if you would drop an empty small bottle of water in still water you might not get as big as a wave as if you dropped the clay barrier, which would be a lot heavier. (My prediction) However, when given roughly the same pressure and a consistent up and down movement the small water bottle created more waves in the water than the clay barrier and the marker, making the balls go to the edge of the tub faster.Therefore, the bigger the surface area causing the disturbance the larger the waves are.


Further Inquiry:
I think this lab was pretty interesting, but if I were to do it again I might want to try some of my classmates labs. One that I found was pretty cool was the one where Sophie used many different liquids to see where the waves would turn out best. It would be pretty interesting to watch how the density of the liquids change the way waves are being made, if they are being made at all. Another lab I might want to try is the one in the tank, where you observe the waves being made when all you do is move the tank back and forth. Then they kind of go up on the sides, and I think it would be really amazing to observe that and find a scientific explanation to why the waves act the way they’re acting. I would also want to try a lab where you drop an object into water from about half a meters distance, and then watch the waves being made. This lab would kind of fit with the one I just made, like a sequal, nr 2. It would be an interesting continuation to see if the clay barrier and the marker make more waves than the empty small water bottle. Off course, this would be a very messy lab, so it would probably be better to do it outdoors in spring sometime, instead of spraying the whole classroom. :)

Ball/Wave Barrier Bouncing Wall Pattern Lab

What happens to a wave as it hits a surface it cannot pass through?

When a wave hits a surface it cannot pass through it bounces back, in the opposite direction creating patterns. Depending on the angle of incident, the angle between the incoming wave and the imaginary perpendicular line, the angle of reflection was formed. The angle of reflection is the angle between the reflecting wave Although we did our lab with balls and not waves, we could still see some patterns being created when the balls bounced back from the wall/vertical surface. When we traced the balls path, we noticed that after the ball encountered a barrier it would slow down and lose energy.

Does energy (density of the ball) affect the waves path?

In the lab Tristan and I did we didn't notice anything about the balls having different paths because of different densities. We used three types of balls; the small metallic ball, the big marble and the biggest styrofoam ball. When we traced the balls it looked like they all took approximately the same paths, just that they were thrown at different angles. However, I think that it would make sense for a ball to travel differently with more density than with less density, so maybe if we had tested how the balls bounce back from a meters space instead of just the width of an A3 piece of paper we might have ended up with some different and more accurate results.

How is the angle at which the ball (wave) hits the wall related to the angle at which it bounces back?

The angle the ball was thrown at affected how it bounced back majorly. The angle of incidence causes the angle of reflection, so the reflected wave or the path of the ball after it hits the wall is the reflection of the angle at which the wave first hit the barrier, or the ball first hit the wall. The angle of this action is the angle of incidence.What Tristan and I noticed was that it was kind of as if there was a line at the point where the ball hit the wall. We later learned that this line is called the reflection line. Then, the ball would follow the exact path back, but on the other side of the line- reflection. It's kind of like symmetry, since the two lines were almost symmetric.

How do Waves Interact in a tub of water with:

1) No barriers
2) One barrier
3) Two barriers

This week in science class we did a lab studying waves, and how they travel through water without barriers, with one barrier and with two barriers. We used a small tub, water, 2 pens, and clay barriers. What we did was fill up the small tub halfway with water. Then, we used 2 pens to make up and down movements in the tub, causing waves. We did this continuously and observed the waves the pens motion made. Our first experiment, with no barriers, went pretty straightforward. We created waves with two pens on opposite/different corners of the tub, and watched the waves the movement of the pens created. Basically, the waves traveled until they met an obstacle, such as the side of the tub or another wave. When the two waves interfered, they only overlapped a small part, and then disappeared. We tried moving the pens faster and faster up and down and they made even more waves, but they still went invisible after they interfered. That is probably because there's a stronger force on the opposite side, like the stuff we studied last year. We did three tests and then sketched them in our notebooks. Then we tried it with one barrier. Just as I had suspected, the waves couldn't travel through the barriers. This also meant that the waves now had three obstacles; the side of the tub, the opposite wave, and the clay barrier. The waves continued traveling, but they were weaker than the first round without barriers. We did three tests putting both the barriers and the pens in a different position. When the waves went around the barriers they caused diffraction, or the bending of waves as it hits a barriers. The waves then split up and caused ripples over the half the tub. Lastly, we added another barrier, so that we had two barriers, the side of the tub and the opposite wave interfering with the movement of the waves. We did several tests, and they were all pretty similar to each other. The waves couldn't pass through the barriers, and they were even less strong than the ones with one barrier. Diffraction split them up even more than with only one barrier. One experiment we tried that was really interesting for me was when we had one pen at a corner of the tub, and then closed it in there with the barriers. All the waves inside the enclosed area started moving really fast, and bouncing off barriers and walls, while the other pen, outside the enclosed area, made large waves covering almost half the tub. The two waves never inter-lapped, it was as if they were made in two different tubs. This really shows how effective barriers are and how well we are able to control waves.

Below are some pictures I took from this experiment.