David's Science blog
Lab
Hypothesis: I think that the weight and temperature will affect the appearance of the crater.
Materials:
Tray
Flour
Marbles
Ruler (cm/mm)
Computer.
Meter stick
Procedure
Mark 30, 60, 90, and 200 cm on a meter stick. Then, put the ruler vertically inside the tray full of flour. Then take your marble and drop it into the flour at 30 cm. Then repeat this process 3 times for 30cm drop. Record the diameter of the hole in flour the marble made and also how deep it is. After that repeat this process for the other drop heights.
Data Table
On next post
Conclusion
In this experiment I discovered that the higher drop height of the meteor the deeper hole it will create, however the diameter of the hole is not affected by this. I think that this is because a meter will burst on impact, while our marble won't. The deepness of the crater is affected by the speed of the marble and the speed of the marble is affected by the height it is dropped from.If the marble was dropped from an even higher place the crater would not increase in diameter, but will increase in depth until the point that the marble is so deep that the hole it makes will collapse on it.
Further Inquiry
I think that this experiment went relatively well and there aren't many ways to improve it, however I think that we should have tested even bigger heights to see if there is a difference, also I think that we could have measured the crater more accurately.
Current Events
On March 28 astronomers got the first glimpse of of a dormant black hole become live. Scientists think that the explosion of a couple stars caused it to restart. If this black hole sucks in a star, it could stay live for another 1000 years. If this happened to the dormant black hole in the Milky Way were to start Earth could be in danger. However that is highly unlikely.
The black hole is sucking in a large amount of gas and jetting it out again. If the black hole in the milky way started, that is also what it would do, except that the jet of gas it is expelling would be 40 times stronger than the jet of gas the other galaxies would be.
However, this is not actually the first time this has ever been caught on camera. This was done at 3 other occasions but Nasa's Swift satellite caught it minutes after it happened, while on other occasions they caught it days or weeks later. Maybe that is because they are so far away. This one in fact is 3.8 billion light years away.
Current Events
Moon Buggy
The Moon buggy is a 1 horsepower vehicle. No doors, no windows. Just some equipment and painful chairs. If anyone else made it it would probably cost 10 bucks. But it was made by Nasa, and it was for the Moon, so it cost 20 million US dollars, mind you, that was the day when an average car only cost 3000 or so. However, on the moon the moon buggy was very useful, expanding our knowledge of the moon. The only drawback was that because the moon buggy didn't have any extra supplies, the NASA team could only go to a distance where they could walk back from.
However, the new moon buggy has solved the problem. The new moon buggy costs 4.5 million dollars, looks like a truck with a round cabin, however it is a very high tech piece of equipment. On earth it weighs 4 tons but on the moon it weighs 760 kilos. Its top speed is about 16 kph. The moon has 12 wheels, and a motor for every other wheel. It has powerful computers that can make it navigate ditched and rocks. Mos importantly, it is sealed and has its own air and food supply, making it be able to travel much further much faster ans much safer. However, if you do get bogged down you can exit the buggy through a door that leads right into your space suit. No more hopping around trying to get it on. All you have to do is stretch you legs our in to the suit, put your arm through the top part and start walking. The space suit would be full of supplies that hopefully is enough to get you back. However breaking down is very unlikely.
Its tires are from a tractor, chosen for their toughness.. It can change its height off the ground for bumpy terrain. Its so good on hard terrain, that even on earth weighing 4 tons it can climb over 30 degree slopes. However, all this is useless since the moon missions have all been canceled. The 4.5 million dollar piece of modern machinery will just go to a warehouse for the rest of its life.
Moon Phases
We see different parts of the moon each nght because we can only see the moon when the sunlight is reflecting off it. So as the moon orbits the earth, the sunlight hits less or more of the moon, so we sometimes see a lot of the moon and sometimes we don't.
A lunar month is the amount of time from 1 full moon to the next.
Sun
2. Then the Southern hemisphere gets little or no light, so it winter there, while it is summer in the North.
3. There would be less heat because it would be more spread out and less concentrated since it shines over a bigger area.
4. The very middle of the North and South poles are the coldest because the sun almost never shines there, and if it does, only the very edge. While the equator is the hottest because it gets the full blast of the sun all year round.
5. When it is winter in the Northern hemisphere the toothpick shadow would be longest, while when it was summer in the Northern hemisphere the shadow would be shortest.
6. If the sun is directly above a square, it gets the most heat and light, while when its toward the south or north of the square, the heat and light received is less.
7. Seasons are cause when the sun is shining at different parts of the world far and close to a certain place. When the sun rays are shining closer to a certain place its spring then summer, but as it goes farther away is fall and winter.
Use your observations of an Earth-sun model to write an explanation of what causes the seasons.
Unit Reflection
The study of waves effect everyone. If no one studied waves there would be no internet, phones, RC toys. Planes wouldn't exist because they would have to fly close to the ground in order to navigate. Human kind would have never broken the sound barrier in flight, nobody would be sent to space. Without the study of waves humans kind would be reduced to living in small towns. Learning only what that small town knew and never going anywhere. Living on meat cooked on fire and surviving on the heat of fire in the winter. Making your own clothes. Everyone would be farmers of hunters.
Food Irradiation
The students of 7B from the International School of Belgrade propose that the labeling on irradiated products should also have a detailed description of the effects of radiation and the potential harm that could come across from it. Also, education awareness of the subject should be spread throughout the world of the dangers and possible long term effects of irradiated foods. We believe that there should be a choice for the customer whether they would like to experience this new discovery of the irradiated food.
The problem with food irradiation is that irradiating food uses radioactive technology which could be harmful, and along with getting rid of germs, it gets rid of some of the vitamins.
Pros and Cons of food irradiation:
Pros:
Food irradiation has stopped almost 76 million illnesses yearly. Before food irradiation was invented 25% of the food that was produced was spoiled or had food related illnesses on shelves or on their way to shelves. Without 25% of the food being spoiled, there is more food at cheaper prices.
Cons:
Irradiated food has 10% less nutrients then fresh food, and while irradiated food does have less food borne illnesses, it gains other ones that aren't necessarily and better. Also, even though it is FDA (Food and Drug Administration) approved, it still hasn't been tested on the long run.
If you gave me a choice from irradiated and fresh food, I would probably pick the fresh ones because they usually have more taste, and so my parents don't blame me for eating unhealthy.
My thinking didn't really change through the debate because I still don't really care if the food is irradiated or not. I think the debate was a good idea because it let me see other peoples point of view.
Noise Pollution
Noise pollution is when there is a lot of noise (over 80 dB) in 1 area for a long period of time where someone is while not wearing anything covering their ears for a long period of time. This may sound like something from a from a sci-fi book but it still happens, in factories, target shooting, grenades/bombs, rockets, rock concerts, and wars. Noise pollution will be painful for you ears and it could cause hearing damage, and temporary or even permanent hearing loss.
Before, no one knew or cared about noise pollution, and as a result ex-soldiers who had been in a war over 10 years ago can be know to have bad hearing or if their unlucky, no hearing at all. Hearing damage is cause when a extremely loud sound (over 120 dB) is heard by a naked ear, which could damage or burst an eardrum, which is essential for hearing. Or it could damage hair cells, something that turns sound into electric signals that is then picked up and read by our brain and we hear the sound. But if these hair cells are damaged they will not grow back.
But now thanks to science and new technologies scientists are inventing new ways of stopping these problems. For 80 to 100 dB sounds you might as well just cover your ear or listen to some music with headphones. But for up to 110 to 130 and over you should have a Styrofoam earplug. This is very cheap but yet effective to keep workers ears from getting damaged and is found in almost every single factory where there might be loud sounds. Even if some aren’t used and are just there to get past health and safety.
For anything over that you should have headphones. And if it’s even higher than 190,(concussion grenade and some other types of bombs) scientists have invented a special ear plugs for the army that uses tiny filter that can deaden most sounds in a c war down to 22 dB. Scientists have also found out that there are sounds beyond a human’s ability to hear but yet some animals with sensitive hearing can hear it as a very annoying noise. Dogs are one of these species and trainers use special whistles which can emit this high pitched sound.
However, these inventions aren’t perfect. The cheap Styrofoam ear plug will be completely useless if there was a sound over 130 for a long period of time. Also the people who designed this small ear plug didn’t consider what workers who might do this for a living would be doing while wearing these ear plugs. Mainly, they would be moving around. But moving around is a big problem for these earplugs because the material they are made of is extremely squishy so it will mold to the basic shape of your ear, just slightly smaller, but once it’s in your ear it will not re-inflate so that while it’s in it is useful, but a small move will cause it to fall out onto the dirty ground. If this happens it will be dirty and its sticky surface will be dirty so you will get another. But sooner or later it will happen again, mostly sooner.
You could solve this problem by getting your company headphones, but if you have a lot of workers it won’t be cheap, and most will stick to the cheaper option. So there is something that often happens to humans, a perfect design ruined by the smallest thing.
Lab Report
- Tuning fork (320E)
- Window
- Locker
- Table
- Aquarium
- Wall
Procedure:
Step 1: First of all you will need a partner to help you with the lab.
Step 2: When you have a partner, gather all of your materials that you will need to complete this test.
Step 3: After gathering all of your materials needed for the test start the lab.
Step 4: Bang the tuning fork on a table and then put it standing on it and put your head to hear the sound of it through the table, repeat this step with all the materials you chose to experiment with.
Record and Analyze:
Medium | Density | Sound |
Wall | .2 grams | Low pitch with no vibration |
Table | .65 grams | Medium vibration with medium pitch |
Aquarium | 2.5 grams | High pitch with no vibration |
Window | 2.5 grams | High Pitch with lots of vibration |
Locker | 3.9 grams | Medium vibration with high pitch |
Conclusion:
Current Events
Sound Lab
How People Produce Sound
Earthquake Saftey
Tsunami Warning Systems
Tsunami is a natural disaster that happens all over the world in oceans and seas. Tsunamis are caused by earthquakes, underwater volcano eruptions, underwater landslides, and huge icebergs breaking off from glaciers. A big tsunami can flood coastal villages, causing the water to become undrinkable, people to be stranded on rooftops, supplies non-existent, trees uprooted, houses smashed. Here are a few things you should know about tsunamis, it is the Japanese word for harbor waves. They can travel up to 450 miles per hour and can get up to 100 ft high. About 80% of all tsunamis happen in the Ring of Fire in the Pacific Ocean. At top speed a tsunami can cross the entire Pacific in one day. Away from land tsunamis are only a foot high and look the same like any other wave, but in a tsunami the top part of the wave travels faster than the bottom, causing it to grow higher. If you are on a beach and you see the water being sucked into the ocean a tsunami is coming and quickly warn others and go to higher ground. This is how a little girl saved hundreds of people that would listen to her, and got in the news. But don’t be the religious family of four, who got in the news by watching the water get sucked away and followed it until they were crushed by tons and tons of water. A tsunami is made of many waves, so if the first one hits there could be more to come, and most importantly, NEVER PANIC.
The most practical and most used way to survive a tsunami is to flee to higher ground, and to do this the people have to be prepared, which is why scientists have had to invent a special alarm that starts sounding a siren when it detects a tsunami approaching because before tsunami’s reach land they are just as high as a normal wave so people in boats can’t tell the difference, and only show themselves when they near shore and the water is shallower, when it is already too late for the people still there.
Some warning systems work by using a seismograph to record an earthquake, then it would send the data for the earthquake to officials if there is enough force to cause a tsunami. Then the officials decide whether to sound an alarm or not, but with this system there are many false alarms because sometimes even if there is a big earthquake there might not be a tsunami or the waves could go in the other direction. This system was also repeatedly unable to detect a tsunami which was why the people in Hawaii had no warning when a tsunami came to land and this cause devastation in 1946 and 1960. This caused scientists to try and develop a more reliable tsunami detector so when the next tsunami comes people will be ready for it. Another way people were able to have warnings for a tsunami was from watching animals. In 2004 when India was hit by a tsunami all the elephants ran to higher land due to their more sensitive hearing ability. Another way scientists have been able to tell when there is going to be a tsunami is by putting sensors on the ocean floor which will detect if there is a wave moving too fast or having too much energy. If it detects an alarm will be sent to officials who will decide whether it’s a false alarm or not. These sensors can go to 7000 meters under water and is self sustainable for up to 4 years, so it won’t be too expensive and it won’t cause too much environmental damage.
In 2004 the biggest earthquake in 40 years had just happened in the Indian ocean, the people at the Indian Meteorological Department recorded the earthquake and sent a warning by fax but the warning was not issued until after the tsunami hit the Indian coast. This tsunami cause 230,000 deaths and according to newspapers could have been avoided if the alarm had been issued on time. This is why now scientists and governments are trying to get enough finding to install reliable tsunami systems in poorer countries to prevent what happened in 2004 from repeating. I think that if there were more tsunami warning systems tsunami’s would no longer pose as such a threat to people in countries on the coast, this way it could save thousands of lives.
Lab Report
Guiding Question: Does a seismograph work better with string or wire?
Hypothesis: I think that the seismograph will work better with string because it will be more flexible and it will be easier for it to move left and right under movement.
Materials
· Flat piece of wood
· 2 on foot long pieces of wood
· Thin but long nails
· Hammer
· Saw
· Tape
· Paper
· Wire and string
· Scissors
· Marker
· Circular weights
Procedure
1. We took a foot long piece of wood and hammered 2 nails to stick it onto the side of the wooden board.
2. We took the other piece of wood and put it horizontally on the other 1 foot long piece of wood facing inwards.
3. We attached one long piece of wire or string to the top and side, leaving to the ends dangling.
4. We attach the wires or string to a 5 sq in flat piece of tape as to stabilize the markers movement.
5. We cut holes in the tape so we can put in the marker and attach the wire.
6. We add the weights to the tape.
7. We put pare under the marker and start shaking the board while pulling the paper from under the marker.
Data Analysis
In this lab I found out that the stronger the material and the more weights you put on it the more accurately it will be able to record earthquakes and the less likely that there will be a false alarm. I also found out that in a seismograph the marker isn’t suppose to move so that most of us where doing it the wrong way, but we still got some good results.
Conclusion
In this lab I found out about how seismographs are made and used. I learnt about earthquakes and how their recorded, why their recorded, and how the things that have been recorded are read. On the way I also learnt how to hammer a nail properly and always trust Aleksej’s random ideas. My hypothesis was incorrect and it turns our that’s a seismograph is better if it is more rigid and not flexible.
Further Inquiry
If I were to do this lab again I think I would try more weight to see if that would help and I would see that if the flat piece of tape we stuck the marker through would be better if it was bigger. Lastly I would try to stabilize the part of the seismograph where the 2 pieces of wood was stuck to the board because that cause the marker to life from the paper.
Lab Report
Hypothesis: I think the denser the liquid the slower the wave.
Materials:
- Water
- Sunflower Oil
- Sugar
- Tub
- Timer
- Recording System
- Help From a Friend
- A half and inch diameter tapping tool
- Ruler
- Tape
Procedure:
- Take your tub and tape you ruler onto the bottom, putting the 1 on the cm side facing you.
- Fill you tub with about 3 quarters full with water.
- Set your timer for 10 seconds.
- Ask you friend to count the wavelength.
- Start tapping the water with your tapping too and count the frequency.
- When 10 seconds are up record the wavelength and frequency and then find out the speed and record that too.
- Do 3 tests before switching mediums.
- Put sugar in until the water is sticky.
- Repeat the steps 3 to 7.
- Then dump the water and pour in the sunflower oil.
- Do the steps from 3 to 7 again.
- Your experiment is done.
Data Analysis:
Water | Sweet water | Sun flower oil | |||||||
Trial | Hz | Wave length | Speed | Hz | Wave length | Speed | Hz | Wave length | Speed |
1 | 3 Hz | 2.5 cm | 7.5 cms | 3 Hz | 2 cm | 6 cms | 3 Hz | 1 cm | 3 cms |
2 | 3 Hz | 3 cm | 9 cms | 3 Hz | 1.8 cm | 5.4 cms | 3 Hz | 2 cm | 6 cms |
3 | 3 Hz | 3.2 cm | 9.6 cms | 3 Hz | 1.7 cm | 5.1 cms | 3 Hz | .75 cm | 2.25 cms |
Conclusion:
Through this experiment I found that the denser the liquid is, the smaller the wavelength and slower the wave. I support this because with water, the lest dense liquid, the average speed was around 8.5 cm/s and the average wavelength was around 2.8 cm. In the sweet water, which was the 2 densest liquid the average speed of 5.5 cm/s and a wavelength around 1.8 cm. For the sunflower oil, the densest liquid, its average speed was 4 cm/s and wavelength 1.25 cm.
Further Inquiry:
If I was to do this experiment again I would use more mediums and include things like ropes. This way I could see the difference between mediums much better and this way I might be able to prove myself wrong and that's good because in the process I would learn more while making a bit of a mess.