As promised, here is a link to the spring animation demonstrated in class. By adjusting the sliders, you can see the effects of changing the spring constant, gravity, friction, etc. It’s neat to play around with it.
I’ll offer three points of extra credit on the next homework assignment for the first of my honors students who is able to design an experiment and accurately measure the mass of the red, green, and gold weights.
I showed this video to most (maybe all?) of my classes, but it never gets old. This is a trip through the known universe, starting in the Himalaya Mountains and going out as far as we have been able to observe.
The cool thing here is that every planet, star, galaxy, and nebula is presented to scale and as currently located by astrophysicists, so it really is the known universe.
In our physics classes we usually talk about things that are sizes we can comprehend: a ball, a block, a box, a vehicle. The realm of physics goes far beyond that though; particle physics deals with things on a very small scale (molecules and atoms), and astronomy and astrophysics with things on a very large scale (stars, galaxies, and the distances between them).
This nifty animation allows you to fly through the entire scale of the universe, from yoctometers (ym) to yottameters (Ym); that’s 10-24 to 1024 meters. Surprisingly, atoms are not as close to the small end as you might think; there are many things tinier than atoms. Some of those things are only theoretical and have never been observed, so we don’t know if they really exist.
In studying gravitation and Kepler’s Laws, we learn that the time it takes a planet to orbit the sun depends on the radius of its orbit; specifically T2 is proportional to r3. Saturn and Jupiter take longer than Earth’s 365 days to complete an orbit because they’re farther away; Mercury and Venus take less time because they’re closer.
This website will calculate your age on each planet in the solar system; just a fun little app to start off the semester. In case you were wondering, Wahlgren is only 44.6 days old on Venus, and won’t celebrate another birthday on Neptune until the year 2145 on Earth!
See Mr. Wahlgren and tell him you saw this post. Worth an extra point on the first homework assignment of the semester. Must be completed by the time your first assignment is due.
Welcome to the Fryeburg Academy Physics Blog, a joint project between Mr. Wahlgren and Mr. Strahler.
To get started, please read the page entitled About the Fryeburg Academy Physics Blog. It has some information about the blog and its purpose, as well as some basic ground rules.
So we advise you to get involved, check the site often, and let’s have a good semester.
Some of you are still taking the last of your finals, and some of you have already departed. For the seniors and those not taking AP Physics next year, I won’t have you in class again. I’ve enjoyed teaching all of you, and I wish the best of luck in your future endeavors. As you depart, I have a few things I’d like to share with you.
I’m going to tell you a secret now: My primary objective as an educator this year was not to teach you physics.
Yes, you read that correctly. It’s true I want you to learn physics and do good science and things, but there are more important lessons to be gained from a scientific approach to the world. Things like the power and importance of rational thought. Like the universe follows this basic set of rules, and we can describe those rules by using the language of mathematics. Anything that happens will follow these rules, and if you have a basic understanding of them you can really appreciate the beauty and interconnectedness of this world we share.
As you leave, let me share a video with you. This is the famous Last Lecture, given by Randy Pausch. Dr. Pausch was a computer science professor at Carnegie Mellon University, and in September 2006 he was diagnosed with terminal pancreatic cancer. He was 45. His lecture is about achieving your goals and the legacy you leave behind. The video is long, over an hour, but it is well worth your time and I recommend you watch it.
Randy Pausch died on July 25, 2008 at the age of 47.
My Honors Physics classes are trying to estimate how much energy the school uses in a regular week. I found this website, which offers some nice estimates about how much energy various appliances use. Feel free to use it to help you make your estimate.
In Honors recently we’ve been looking at electricity, and the question was posed to me: “how much current does it take to kill a person?” I didn’t really have an answer that I was sure of, but this morning I found an article that has one: just 7 mA, applied directly to the heart for 3 seconds, will do the job. That is 7 milliamps, about 60 times smaller than the current flowing through one of the small light bulbs on the circuit boards when connected to the 3 V batteries.
And it was Adam Savage from the Mythbusters that said it, so it must be true!
I’ve written before about how nuclear power is the best carbon-free electricity source at the moment. Not to say that others like wind and solar will never work, but they’re not viable to use on a large scale at the moment, and won’t be without several more years and a lot more money for research. If we’re going to cut carbon emissions drastically starting soon, nuclear is the only way to go.
There is still a large percentage of the population that resists nuclear power, and this is because most people are just uninformed. I’ll admit that nuclear stuff is scary, and if something goes really wrong the results are really bad. One of those really bad things happened at Chernobyl in 1986, and people are afraid it might happen again. Rightfully so, I think.
The big problem with the public resistance to nuclear power, though, is people like Ken Gale. As far as I can tell, he’s not an expert on anything except comic books, yet he has written this article about the safety issues of the nuclear power plant at Indian Point, New York. He says a lot of scary things, and anybody who reads this would be crazy to embrace nuclear power.
The problem is this: barely anything he’s said on that site is actually true. His claims that the plant regularly releases radioactive gas, it releases radioactive and thermal pollution into the river, the high level waste is stored in open pools, and that New York wouldn’t notice if the plant was shut off are ludicrous. None of those statements is even remotely close to fact. The author claims to have researched the page, but he doesn’t list his sources so I don’t know where he got this “information.”
If you’re going to oppose nuclear power, at least do some real research before you do. Inform yourself before taking a stance either way. Be skeptical of any claims for or against, do your homework, and make up your own mind.
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