goalkeeper0

Sure, it will float. Let's try.

Very violent, but I have learned that cats end up at the wrong end of many physics demonstrations by now...I wonder why cats and not any other animals?

In early September, in the very beginning of my time in AP Physics C, I was hesitant about the workload and difficulty of the course. When Mr. Fullerton introduced integrals to us for the first time, I knew from then on that the class would be no piece of cake. The funny thing looking back is that I enjoyed the calculus parts of physics by the end of the year very much. With a solid calculus background, the "hard math" aspect of the AP did not seem so hard. For me, the hardest part of the class was reading the problems and deciding in which direction to think. I had trouble reading the questions and immediately knowing which equation to use first, which equation to use second, and so on. I tried helping myself by reading the textbook and taking notes, along with making flashcards for the equations. By the time the AP rolled around, I was nervous, but felt prepared to do well. After taking the AP, I am happy to say that Mr. Fullerton prepared us very well as he made our tests harder than the AP itself. All in all, I look forward to the physics I take in college. I hope that from the AP tests I get some college credit; but if I do not, I know that I will at least have the background necessary to succeed in physics mechanics and electricity/magnetism. I wish the best to all of my AP Physics C classmates and the future students of AP Physics C! Go Physics!

As graduating seniors, we are getting old. No more high school, it's off to college! But, just how old are we? On the earth we are about 18 years old, give or take a few months. Because the other planets are different distances from the sun, they have different periods of revolution. Therefore, in relation to many planets we are very young (Neptune) or very old (Mercury). A planet's period is given by: = distance from planet's aphelion to sun = distance from planet's perihelion to sun Periods of planets (in Earth years): Mercury: 0.241 Venus: 0.615 Earth: 1 Mars: 1.881 Jupiter: 11.86 Saturn: 29.46 Uranus: 84.32 Neptune: 164.8 Age of 18 year-old earthling on planets: Mercury: 74 Venus: 29 Earth: 18 Mars: 9 Jupiter: 1 Saturn: 0.6 Uranus: 0.2 Neptune: 0.1 As period increases, one's relative age on that planet decreases. So, as seniors, we may be walking the stage soon; but on Mars, we would only be half-way there!

I have always wondered this also. I never imagined that pruney fingers are the body's response to increase mew. Very interesting!

Happy (belated) National Donut Day! This American day of celebration for sugary breakfast rings occurred yesterday on June 7. Yesterday, people from across the nation stopped by Dunkin Donuts to receive a free donut. These consumers devoured the sticky treats without thinking about the history or science behind the donut. But, the history and science, particularly physics, is interesting. So, I will now discuss the connection between donuts and physics. The Dutch brought the idea of deep-fried balls of dough over to the western hemisphere. Originally, the dough balls were spherical, solid, and small. Over time, as American confidence grew, potion sizes also increased. Donut makers tried making bigger and bigger donuts to attract more customers. The physics of heating, and heating efficiently then came into play. The large donuts burnt on the outside and remain uncooked in the middle. The dough wads did not heat evenly. Producers couldn't match the demand for larger donuts, because they couldn't prepare larger donuts. One man by the name of Captain Hanson Gregory then changed donut history. Captain Gregory made a circular cutter and removed an inner circle from the dough. And, the ring shape of donuts today was created! The modern donut with an extracted center exists solely because one man thought about physics. Captain Gregory knew about thermodynamics and heating. He knew that for Americans to eat larger donuts, larger donuts needed to become more spread out. By increasing surface area, the donut heats and cooks faster and more evenly. To all of those donut lovers out there, thank Captain Gregory for the design of the classic ring donut.

Where are atomic clocks used?

Sounds like a very interesting summer job

Population concerns on Earth are leading scientists to inquire whether colonizing Mars is possible. As of now, over 78,000 people have applied to leave Earth forever and live on Mars. Mars One, a nonprofit organization, is sponsoring the colonization with a take-off date sometime in 2023. Out of the applicant pool, four will be chosen to send first to Mars. The first four will lay the groundwork for a permanent colony. Two years after the first four land, Mars One would send up more people to the colony. With the application process underway, it seems as though scientists have discovered ways for humans to survive on Mars indefinitely. However, this is not the case. Many, many concerns exist such as how will the colonists feed themselves? Will crops which grow on the Earth also grow on Mars? The first settlers of Mars will most likely be farmers. Yes, they will be astronauts; but, if survival is of any importance to them, they will learn to farm in order to eat. Research which has been conducted supports the idea that growing crops is possible in microgravity. However, those working for NASA do not know to what extent the gravity of Mars will effect crop growth. Also, Mars' surface only receives about half of the sunlight that the Earth's surface receives. Will plants be able to grow with limited sunlight? On top of the already limited sunlight, pressurized greenhouses would be necessary to grow crops. The greenhouses would block out more light. So, additional light would be necessary from other sources than the sun. What would power additional light sources? How would that power be generated and sustained? Radiation would also be a problem faced by those on Mars. Mars does not have as strong of an atmosphere as the Earth. More radiation reaches the surface of Mars than the surface of the Earth. Inhabitants would need a way to reflect the radiation or shield themselves from the rays. To live on Mars, man must master the art of agriculture in microgravity. Feeding the inhabitants of Mars is one among many more necessary tasks of survival. As of now, research is still being conducted. The 78,000 who have already showed interest in living on Mars are a bit stupid or extremely bold. With current technology man would not survive on Mars. I do not doubt though that technology will develop in the near future for man to successfully live on Mars.

Hmm. The use of physics to shoplift, I wonder why we don't learn this in class...

Pale people of the world, beware of the shining, warm sunlight! UV radiation, with a shorter wavelength than visible light, is absorbed by skin causing a sunburn and long-term skin damage. The Earth's atmosphere filters the majority of UV rays before they reach pasty humans; however, UV rays still penetrate the atmosphere. Exposure to UV radiation changes based upon altitude, distance from the equator, time of day, season and amount of cloud cover. At noon, with the sun high in the sky, sunscreen is heavily advised. How does sunscreen protect people from UV radiation? Sunscreen includes organic and inorganic compounds to reflect, scatter, absorb and release UV rays. Inorganic ingredients such as titanium dioxide and zinc oxide form a physical barrier between UV rays and skin. Because of this barrier, less rays penetrate deep layers of skin. Organic ingredients absorb UV rays and release them as heat. There are two different types of UV rays. UVA rays penetrate multiple layers of skin and cause long-term skin damage. UVB rays cause the visible sunburn and effect top layers of skin. Both types of UV radiation are bad. The SPF of a sunscreen is the measured UVB protection of the formula; there is no standard for UVA protection. A broad spectrum sunscreen protects against both types of rays. A sunscreen with a SPF of 15 means that one could spend 15 times as long in the sun before getting burned compared to the time necessary to get burned without sunscreen. Why wear sunscreen? Well, besides the fact that prolonged exposure to UV rays can lead to skin cancer and eye damage, UV radiation also can reduce the effectiveness of one's immune system. This fact seems strange. But, since UV rays displace or kill some cells necessary to trigger immune system responses, the body's ability to fight infections decreases. So, as we all await the end of school and the sunny days of summer, remember the importance of applying sunscreen!

This is a great post! I agree that this is the hardest AP I have taken also.

I definitely formed some college study habits while taking physics this year

As senior year comes to a close, brain space previously reserved for memorizing lists of vocab or challenging physics concepts has been filled with plots for senior pranks, senior runs, and so on. As of now, our senior runs have been quite brief, but I remember the senior runs of the past being both long and successful. As a freshman, I remember being caught in the hallway as I heard the shouts and footsteps of hundreds of seniors coming my way. Senior runs, or more like senior stampedes, can be heard from far away which is good so that small, tiny freshmen have time to hide in the bathrooms and not get trampled. Potentially, one caught in the middle of a senior run could get seriously bruised and battered. Stampedes are dangerous. I touched a bit upon stampede physics in my Black Friday post a very long time ago, but I found some more information about how physicists are studying crowd dynamics. Physicists look at fluids to help them understand crowd dynamics. Physicists have found that crowds behave as fluids with three different types of flows. The first type of flow is laminar flow. Laminar flow is a steady flow which resembles crowd dynamics when an area is undersaturated with people. The next type of flow is stop-and-go. Stop-and-go flow causes spurts of people to leave an area at a time. Waves are created in the crowd. The worst flow type is turbulent flow. Turbulent flow is the result of pressure buildups. Turbulent flow leads to "shock waves" which can push people up to 3 meters forward. I'd say that most senior runs do not reach the turbulent flow stage. However, given the velocity of the crowd, and the combined mass of the people in the crowd, these runs can definitely cause damage. The momentum of the stampede is enormous, and tiny freshmen are wise to seek shelter in nearby restrooms. http://physicsbuzz.physicscentral.com/2013/01/brazil-nightclub-stampede-trampling.html

I agree with Dave. The Kerbal Space Program is really cool and I have definitely learned a lot from it, but other options would be nice also.