Craters lab

GUIDING QUESTION:
What are the factors that affect the appearance of impact craters? How do scientists use craters to tell the relative age of them?
HYPOTHESIS:

I think the age of the crater affects the roughness. Also i think the larger the meteor the bigger the crater.

MATERIALS:
safety goggles, tray, flour, notebook, spoon, small and large marbles, meter stick, ruler, excel and word.
PROCEDURE:
1. Put on goggles and apron. Fill the pan with 2.5 cm of flour.
2. Drop a small marble into the flour. What did you observe? Drop another marble again. What happens when they overlap?
The marble creates a small impact. You can hear it and it sends waves throughout the whole tub. The ejecta goes a little farther than the marble all the way around. When they overlap, they overlap on debris and create a small mound. In real life, this could be extremely disastrous. It also creates a bigger crater in a stranger shape.
3. Drop the larger marble into the flour. What did you observe? Drop another marble again. What happens when they overlap?
When you drop the larger marble, it creates a much larger impact and the ejecta flies everywhere. When they overlap, they create a half-moon type shape.
4. Think about the guiding question. What does affect the appearance of an impact crater?
Just from dropping the two different-sized marbles, I can see that the size of the meteor definitely affects what the crater looks like. The larger the marble, the bigger the crater, and the deeper the impact is.
5. Decide on which materials you will use and collect them all to take to your station. You will make a model to test the guiding question.
6. You will need to collect some qualitative (using your senses to make observations) and quantitative-numerical data (Height of drop, mass of the object, diameter of crater, depth of the crater, length of ejecta - if possible to measure, etc...)
7. Make a data table (below)
8. Run your lab according to the method provided.
9. You may wish to take pictures of each impact to use later in a blog post, or you may sketch the results in your notebook.
10. Collect the data needed and enter it into the table.

Trial	Height of Drop	Diameter	Depth of Crater
1	30	1.9 cm	0.7 cm
2	30	2 cm	0.4 cm
3	30	1.7 cm	0.7 cm
average	30	1.87 cm	0.6 cm

Trial	Height of Drop	Diameter	Depth of Crater
1	60	3 cm	4 cm
2	60	2 cm	1.8 cm
3	60	2 cm	2.4 cm
average	60	2.34 cm	2.73 cm

Trial	Height of Drop	Diameter	Depth of Crater
1	90	2.5 cm	2.7 cm
2	90	2 cm	2 cm
3	90	2.3 cm	2.3 cm
average	90	2.27 cm	2.34 cm

Trial	Height of Drop	Diameter	Depth of Crater
1	200	2.1 cm	3 cm
2	200	2.4 cm	2.7 cm
3	200	2.8 cm	2.8 cm
average	200	2.43 cm	2.83 cm

DATA ANALYSIS:
1. Is your hypothesis about what affects the appearance and size of craters supported by test data? Explain why or why not.

I think that my hypothesis covers most of the factors in the appearance of craters, just the one that I didn’t mention that I realized during this lab was when two craters overlap and create a different-shaped crater.
2. What does the data reveal about the relationship between crater size and velocity of impactor?

Well, we didn’t necessarily test the impactor velocity, but the farther away from the tub the impactor starts, the more speed it gains. This works well with our data, because the further away we dropped the impactor, the deeper the crater was, and it tended to have a bigger diameter too.
3. What does the data reveal about the relationship between ejecta (ray) length and velocity of impactor?

The same thing applies to this – the greater the velocity is that the impactor is coming at, the greater effect it’s going to have on the surface. In this case, it creates a lot of ejecta.
4. If the impactor were dropped from 6 meters, would the crater be larger or smaller? How much larger or smaller? Explain your answer.

It would be a lot bigger. This is because it has time to gain speed as it falls, because it is a greater distance than 90 cm, for example. Then, when it hits the surface, it creates a deep and big crater, with lots of debris (ejecta) coming from it.

CONCLUSION:

Our hypothesis was sort of correct. From this lab i learnt speed, size and other variables affect the crater greatly. I think this is a valid statement because the tests were very realistic.
FURTHER INQUIRY:

I think that one thing we could've done better is the variables, we didnt have very many constant variables, and even those that werent supposed to be changed ended up changing so i think that changed our results. Although we had some odds in our data, you can still get a picture of changes so we still learnt from this lab.

Moon phases

Guiding Question: What are phases of the moon? Why do they occur?


Hypothesis:The moon phases of the moon are basically the differences in shades allowing us to see only a certain area of the moon.


Materials:

1. flashlight
2. model of earth
3. model of moon

Procedure:

1. Place the flashlight about one meter from the earth.
2. Place the moon between earth and the sun.
   
3. shine the flashlight and observe different phases
   

Analysis:

1. When investigating the simulation, the moon clock, and/or the model, what did you notice about the phases of the moon? Why do we see different parts of the moon each night?

The moon is constantly travelling around earth, and depending on the allignment with the sun and earth, we get different shades causing the phases.

2. How well did making a model help you understand the phases of the moon? What are some disadvantages of using models?


Using a model is more of a hands on activity. I really enjoyed this because i got to see for my self how the whole process works and having the flashlight helped even more. This lab was a great recreation.


3. Scientists are thinking all the time about how they can make models of objects that are too small or too large to see: Can you think of another way to make a model to represent the various phases of the moon?


I think that if they were to get the scaling right and have sophisticated motorin, tilts etc. they could get very precise information.

4. What is a lunar month?

A lunar month is 29 days that it takes for the moon to make a complete cycle.


Conclusion: In conclusion, i saw how we see the moon phases and what makes them what they appear to as us. I also saw how much the allignment of the sun moon and earth affects these phases.


Further Inquiry:




3. What cause a tide?


Tides are caused by the moons pull on earth, since it cant pull the whole planet it pulls the water around with it which is very interesting.

earth and sun observation

Guiding Question: What causes the seasons? How does the tilt of Earth’s axis affect the light received by Earth as it revolves around the Sun?

Hypothesis:I believe the tilt of the earth and ultra violet rays affect the seasons.

Observing: When its cold in the northern hemisphere(winter), on the opposite side, the southern hemisphere ultraviolet rays are concentrated. When its warm in the northern hemisphere the southern is cold so it has a opposite relationship.


Inferring: The coolest places on earth constantly, are the poles. When it’s summer in the Northern hemisphere

Predicting: We predict that when the toothpick is at its longest time of the year, it will be Summer, and the shortest time will be Winter. This is similar to the Summer and Winter solstices.

Drawing Conclusion: It all depends, when the square, used from the torch, gets closer to the Earth, it gets colder, and depending on how close you put the square to the Earth, it will get even colder. On the other hand, when the squares are farther away from the Earth, it get warmer, then slowly, hotter.

Irradiation

In class we learnt about irradiated food, after a brief introduction and once we got an idea of what irradiated foods were, we were given couple minutes to learn about either of two sides of irradiation, the good, or of course, the bad. Once we have studied our topics we were given a different way of showing everyone what we learnt, we were put to debate against 2 people of opposite belief.

Me and Roy, were set to fight and display the cons of food irradiation going against Lilla, Teodora and Monica, who were pulling through the good sides.

"Food irradiation is the process of exposing food to ionizing radiation^[1] to destroy microorganisms, bacteria, viruses, or insects that might be present in the food."

As the definition above states, it kills many harmful particles in our food, but the problem is, how well can some simple radiation distinguish difference between good and bad?





Pros and Cons of food irradiation:
Pros:
Food irradiation technically does stop many diseases and other,
Food irradiation saves us lots of money spent on throwing away rotten food, dealing with angry people who ate a bad apple and sorting the good food from the bad.
Food irradiation is FDA approved.

Cons:
Food irradiation ruins texture and taste of food.
Food irradiation kills many vitamins and healthy stuff we eat fruit and veggies for.
Food irradiation leaves many of the unwanted bacteria such as the Norwalk which can become a serious sickness.
Food irradiation effects have never been tested on the long run, the longest test was 15 weeks which cannot show any long term effects.
Many animals exposed to irradiated food died or became ill.

I, as a child living in the 21st century, do not make a preference to veggies and fruit over chocolate and chips, that being said when i do choose healthy, why ruin it by taking irradiated food. If i want to eat healthy ill eat the real deal we have been eating for centuries and if i want my food to last long and not risk the .000001 chance of getting sick ill eat a snickers bar.

Honestly, living in Serbia i didn't really know a lot about irradiated food but after this debate i sort of feel more involved in food industry, after watching the food inc movie i saw how many people hated it, but in a way i couldnt really connect and fully understand, for some reason i feel different after this activity.

Tuning Fork Lab

Guiding Question: How does the density of a material affect the properties of sound travelling from a tuning fork?
Hypothesis: The denser the material, the softer/lower the sound
Materials:
1. tuning forks: 512, 320
2. table
3. wooden stool
4. radiator
5. plastic tub
6. white board
7. locker
Procedure:
1. Take the first tuning fork (512) and hit it on the first material. Listen to how loud the sound is. Do this with all of the materials and order them from quietest to loudest in a graph. Find the density of all of the materials you hit the tuning fork on, and determine whether the density had effect on the loudness of the sound.
2. Continue testing with the same materials and and a different tuning fork (320). Graph results.

512	oak table (0.65 grams per cubic cm.)	Locker (7.859 grams per cubic cm.)	white board (0.57 grams per cubic cm.)
OBSERVATIONS	lower than 320, quieter than 312	lower than 320, metallic sound, traveled fast was relatively quiet, echoey	lower than 320, LOUD
320	oak table (0.65 grams per cubic cm.)	locker	white board (0.57 grams per cubic cm.)
OBSERVATIONS	higher than 512, louder than 512	higher than 512, metallic sound, travelled faster than table	higher than 512, quieter, a bit more intense

Conclusion:

Our guiding question was "how does the density of a material affect the properties of sound travelling from a tuning fork?". From the data that we gathered, I can tell a couple of different things. It seems that in most cases, the denser an object is the more difficult it is for a wave to travel through, thus making the sound slower. There are of course some mediums this doesnt apply to, steel is dense, but is very elastic so even though it is dense it travels faster. Our hypothesis is correct from the knowledge we had, from just looking at density out hypothesis was completely correct.

Further Inquiry:

I think that our testing proved the point, but was not as precise as it could be. If i were to do another test with tuning forks i would research how to properly use them to show the difference in difference densities better. If i were to redo this lab again i would be more creative, i would look at many different materials and try to connect some real life applications. I think the only thing i would have done better is following rules well.

Waves Reflection

During this unit,we had an interesting build up to the point we learnt about all waves. We learnt about Seismic Waves, Water Waves, Electromagnetic Waves, and Sound Waves as some of the main topics, accompanied by radio waves, microwaves and many other. A main interesting thing i saw was how many uses waves i never heard of have, and how often i use them, or they influence me.. For example, earthquakes come from seismic waves, before, i was limited when it came to waves, i could never imagine a earthquake was technically a wave. Sound travels in waves, so technically we hear waves! Sound waves can also pollute, this pollution is called noise pollution.

When we drew pictures at the beginning of the unit to see our knowledge so we could compare later, i thought this was crazy, in the beginning of the unit i thought i was smart talking about sound waves instead of water, turns out there was much more too it. When i looked at this picture i literally so an ocean of different waves i missed and i just realized how many waves are around me.

In this unit my favorite part was the amazing organization and build up, we started by drawing our current knowledge, which is both interesting and creative and a good way to reflect later, then later we get into technical stuff. My personal favorite from this unit was how interactive it was, it had a great mix of notes, movies, drawing, doing experiments and other, which helps alot because when you think about a unit you have many different ways to remember it. When i think of the wave unit right now i get around 5 images of the different activities we had.

Next year i would like the 7th graders to have the same experience and nothing to be changed because this unit was so bold and is not one to forget.

All in all this was one of my favorite units and would love to have many more organized in that way.

Irradiation

Noise Pollution

Noise Pollution

Noise is sound that is unwanted, telling us a lot about the meaning of noise pollution already, pollution is an excess that is also unwanted and does not do good. Noise pollution is a problem that we are being affected by in the modern age, although not considered as big or important as other sorts of pollution, global warming or other, it is still a serious problem. Noise pollution sounds funny, and many people do not take it seriously because they don't know what it is. Noise pollution is excessive, loud sound made by either animals or humans mainly coming from either transportation or construction sites. Noise pollution is hidden in a way, problems could be appearing in your life that you did not know the cause of, something as simple as noise pollution could be the cause. Noise pollution affects both our mental and physical well-being in many ways such as hearing loss, aggression and annoyance.

Noise pollution affects many people, some not as much as others depending on the location. In large busy cities noise pollution is all around us, bus's creaking their breaks, and construction workers drilling and expanding new roads and other. Now, you might think you are used to this and that you hear all this stuff every day and it doesn't affect you but you may be mistaken. Did you ever wonder why some people talk about the joy of small villages and how relaxed they are? A big reason for this is the smaller if not non-existing amount of noise pollution. Noise pollution effects can vary from person but have two main categories, effects on our physical health and on our mental health. Mostly, noise pollution causes aggression and annoyance but the effects can grow into more serious things such as hypertension, a cardiac chronic condition and other such as tinnitus, sleep problems and even hearing loss. Hypertension for instance can lead to strokes meaning that noise pollution can be deadly, and guess what, a barking dog is considered noise pollution. The following that i displayed are of course a bit of the extreme cases, but it is proof that it should be taken seriously.

The problem with noise pollution are the effects it brings, it is not so terrible to bare but the side-affects are very serious that is why you should try to avoid areas with lots of noise pollution. People who live in areas with high noise pollution dislike it, and even would pay yearly for a reduction proving how much it is affecting them. This fact was proven by a survey in Sweden saying they would pay 4 euros per decibel yearly to lower the noise pollution.

Earthquake safety

There are several things that you should do if you were in an earthquake. The first, and most important thing, is that you should stay away from wobly, heavy objects, that could collapse and hurt you. This would also include windows, and any other glass objects. You should also move away from bookshelves. One thing that you shouldn't do is to panic. You should also always have a safety kit. In it, you should have materials to help wounds, as well as disinfect them. When in an earthquake you should have food that doesnt expire easily. You should also have a telecommunication device so that you can be found. If you're outside in an earthquake, you should move into an open space, so that you can prevent lethal injuries from collapsing buildings, trees, etc.

My house is very old, so it is not strong. It has many wooden beams that could easily break so if i had the time to i would leave my house go to my backyard and go into the "hole" in my backyard. If i did not have time to leave the house, i would get under the couch because it has a heavy mattress over it and nothing can happen to me. If i had to evacuate the house i would have 4 doors to leave the house and one to leave to the city. If i had to change something about my house i would demolish it and make a new one. My house has many glass tables, windows and beams supporting the structure which would snap easily.

Evacuation plan

Safety plan?

kit?

Issues in your house?

what would you need to change?

Tsunami essay

Tsunamis are one of the most dangerous natural disaster. They kill up to hundred thousands of people. An example of one big tsunami would be the one that struck Indonesia, Sri Lanka and over nearby countries. This tsunami had a magnitude of 9.1/10. This magnitude is of the earthquake that caused it. It is classified on the Richter scale on which 9 is one of the highest levels ever achieved. This tsunami is one of the biggest ever, and unprepared for. The evacuation and warning systems for this tsunami were bad, not notifying people to evacuate on time. Due to this bad preparation, countries began making ways to detect seismic activity in places it occurs often.

The easiest, and most logical way to protect yourself from a tsunami is to reach higher ground, where the water cant reach you, of course to reach higher ground you need to have time. That means that people must be notified at least an hour before a tsunami to be able to flee. Now the question appears, how can we be warned before the tsunami? how do we know a tsunami is coming? Easy, that is where the seismograph comes in, a seismograph is a tool used for detecting seismic activity. Basically, a seismograph is a pen that is not moving that is writing on a roll of paper that is moving so that it accurately displays seismic activity. When seismographs are posted near shores they detect the incoming activity and the people can be notified.

Evacuation is also a method used for avoiding tsunamis. The way it works is that the media and news inform the people about the incoming threat, and tell them where to go and where they can be evacuated. When using this method there needs to be a good way of transferring the information to the people, radio, tv, telephone and other ways are used but nobody knows for sure if everyone will be informed. Even the people that do hear it may not hear it in time. A method used by the government often is sirens and loudspeakers. They set up speakers on poles so that in case of an emergency they can transfer a message through these sirens. These speakers have to be loud enough so that people could hear them though.

Although tsunami warning systems are not perfect, they do help a lot and without them the numbers of lives lost would be doubling, so they still do their job although when playing with peoples lives you can never do your job too good. Modern technology allows us to have seismograph stations at many coasts that communicate to help determine where the tsunami will strike, how strong it will be and many other important factors.People need to learn to take their warning more seriously, because if the people are prepared they can take a warning well. The people must know where to look for information, and must know where to go. Think about what would happen without the warning systems, tsunamis would obliterate everything and nobody would expect it.

All in all, tsunamis kill thousands and thousands of people every year, and our warning systems save the same amounts of numbers. With time out systems for helping those people are getting better but it is still a big issue. I believe seismographs are the best way of foreseeing tsunamis and if they were put in more places they would be a great help. Tsunamis are no joke and need to be taken seriously. the best way that people can get to safety before a tsunami hits and it is being used all around the world.

http://www.stopdisastersgame.org/en/playgame.html

Natural disaster simulator. This game is really cool. Try the tsunami out and write your score in the comments.

Lab Reflection

In this lab we had the freedom to try out anything we wanted which allowed bigger discoveries and better observations. At first we observed the shapes of waves when they are uneffected by outside forces, they created circular shapes. When a barrier is put the wave stops in the line of the barrier but continues around the barrier also in a circular motion. A very interesting observation we made is that when a wave is powerful enough to take shape of the barrier, we first saw this when the waves came out as straight lines after encountering the barrier, to test our theory we used a long strip of curly clay too see if the wave would come out squiggly and it did. From this lab I can confidently say i learnt alot. I also really enjoyed this lab.

No Barriers

When conducting our tests with no barriers we saw that the wave travelled until it naturally lost all speed. We couldnt see if it would bounce of the edges of the pan because it was to week to get to the end.

When we tried with one barrier we saw that the wave got cut off in areas it was being blocked and continued on around it.

Offset your carbon footprint!

http://www.carbonfootprint.com/

Current Events: Pea Sized Frog!?

Aleksej Janicijevic

7B

Science 21/9/2010

Current Events

“Pea sized frogs?!”

This article is about new-found specie of amphibians. The new species of amphibians is a frog called 'Microhyla nepenthicola'. The Microhyla nepenthicola would not be such an amazing discovery if not for its size the average size of the frog is 12 millimeters long. The tiny frog was first found on the edge of a paved road, close to the peak of the Gunung Serapi Mountain in Kupah national park. The frog was named after a flower, but not just any flower, it was named after the flower it lives off, which is named 'Nepenthes ampullariais'. When people say this frog is tiny, they aren’t joking around, in fact they aren’t joking around even when they say it’s the size of a pea, adult microhyla nepenthicola don’t grow over 12 milimeters which is around the size of a pea. What made this frog a difficult discovery is the tiny size, imagine searching for a pea?. Dr.Indraneil Das and Alexander have did not set out in search of a pea sized frog; they came across it by accident. The two scientists wanted to find out whether this specie can be found in other countries and continents so they made teams in 5 continents to try locating the frog.

To sum up I think this article has much more meaning than just a new frog, I think this article tells us about how much we still have to find out about and how much information and new things there are in the world waiting to be discovered. Other than that I am also quite fascinated that a frog could get so small. You never know what could go next we might find carrot sized lions?