
Content Count
2,756 
Joined

Last visited

Days Won
47
Content Type
Profiles
Forums
Downloads
Blogs
Videos
Calendar
Store
Everything posted by FizziksGuy

Great post willorn! By the way, if you're interested in superconducting magnetic levitation, it just so happens that I've managed to pick up a disc of Yttrium Barium Copper Oxide... we could videotape a demonstration and explanation for the Physics In Action podcast  just need to pick up some liquid N2, which isn't tough to do with a bit of advance planning!

The Truth of the Day (and a Bevy of Rotational Physics to Boot!)
FizziksGuy commented on a blog entry in Blog probablykevin
Awesome analysis and a creative way of applying what we're learning to a VERY big scenario. Well done! :wave) 
You're not alone in your thoughts. Our unit on rotation and angular momentum will be, by far, the most difficult of the entire mechanics course. Not only is the material new, it utilizes calculus you're just learning, and it is by no means intuitive  in many cases, it's just the opposite, actually (angular momentum is just one of those things that doesn't really fall into our everyday conceptualization easily). Very shortly, as we get into the heavier stuff, we'll slow down the amount of material being thrown at you each day and balance it with lots and lots of practice so you start to feel more comfortable with it.

Great find Alex  these are the videos I highlighted in your independent work unit. Our version of APC physics is, in many ways, based on Dr. Lewin's lectures. In creating the course format, I relied heavily on his lecture series myself. Good stuff, and a highly entertaining professor. His unit on rotational kinematics and angular momentum are by far the best I've seen, so you'll see our work in class highly correlated with his videos over the next couple weeks! By the way, for those of you with iPods and iPhones, these online lectures are available for free download to watch on your iPod through iTunes...

I've never considered the physics of a dragon before... They'd make great study subjects for kinematics... or even thermodynamics!!!

I had the opportunity to meet with a colleague, teacher, friend and peer on Wednesday, and I'm thrilled with how our breakfast (and work meeting) progressed. Having known each other professionally for close to 10 years now, from a time back before either of us entered education, it was a tremendous experience to sit down and talk about what's working in our classrooms, what we envision for the future, and start putting plans together to achieve that vision. Following breakfast, we settled down to work by looking over what had been completed so far at APlusPhysics.com. I was amazed at how closely our visions aligned... although I probably shouldn't have been since this colleague, in many ways, provided some of the grounding for this website project in the first place. We then spent the better part of four hours working on various parts of the website, each of us contributing in our own ways. I look forward to seeing what we can build together, and am very excited to have another viewpoint for input, contribution, and criticism as we move forward. Thanks Tom!

Had a busy weekend with lots of small successes on the APlusPhysics front... First off, finished up the first draft of the Regents > Graphing Motion page (http://www.aplusphysics.com/courses/regents/kinematics/reg_graphmotion.html) with a couple more sample problems and an interactive Flash mini program demonstrating the relationship between dt, vt, and at graphs (thanks to Tom Schulte for the great graphics!!!). Also, spent some time on the phone with a physics teacher in Illinois working on an article that details our forensics and physics day activity  received some terrific input and ideas that will definitely improve the article. Plus, it's always nice to make another friend in the physics teaching field. Then, got a start on the Regents > Kinematic Equations page... lots of blanks to fill in and still tons of editing and reorganizing to do, but I'm feeling good about getting first drafts created and posted. Hopefully I can keep this momentum going with some time off during the holiday week. Finally, I'm pleased to see the "Homework Help" section of the website getting some use... not only are those asking questions getting the help they need without having to wait for class time, but those who are providing the help are reinforcing physics concepts. "The best way to learn is to teach!"

Great response... Moe is absolutely right. Remember, no net force doesn't mean an object is at rest. no net force means an object won't accelerate  therefore an object at rest will remain at rest, and an object in motion will remain in motion at a constant velocity and in a straight line  unless there is a net force. For example, if a spaceship is moving at 1000 m/s through space, if Superman pushes it forward with a force of 50N and The Hulk pushes it backward with a force of 50N, the forces are balanced, so there is no net force, therefore the spaceship continues at 1000 m/s. Net force = 0 implies no acceleration.

You might have to play for a bit to determine the angles (the math gets a bit more involved), but it's pretty straightforward to see how you could line up a 4N, 4N, and a 5N vector to achieve equilibrium... I've used the vector simulation lab from PHET (http://phet.colorado.edu) to demonstrate how putting a 4N, 4N, and 5N vector together gives you a vector sum of 0. [ATTACH=CONFIG]52[/ATTACH]

You'll want to put it in your own words, but the basic procedure on the lab handout should be quite similar! Other lab report format details can be found at: http://www.aplusphysics.com/courses/regents/labreport.html

Can you elaborate on why you think you should go higher? What factors play into the height of your jump? How could you analyze these factors using what you know about kinematics, dynamics, momentum, impulse, and conservation of energy?

I'm glad you enjoyed the unit... is it something you'd like to do again later in the year?

Would love to hear about physics of JaiAlai!!! :labmate)

THAT'S what I'm doing wrong when I go golfing... more plaid!

Easy enough to fix up... to embed a movie, all you have to do is copy the regular youtube link (not the embed link). Then, in the APlusPhysics editor, click the movie icon and paste your youtube link in there. The editor will take care of the rest! (http://www.aplusphysics.com/forums/showthread.php?16Embeddingvideosintoyourposts) (To make your equations work, I just added the tex and /tex tags around either side of your code. Details available here: http://www.aplusphysics.com/forums/showthread.php?15Embeddingformulasintoyourposts)

The path to solving the problem is already posted... If you are still stuck, can you tell/show us what you've done so far and where you're stuck

Net force F causes mass m1 to accelerate at rate a. A net force of 3F causes mass m2 to accelerate at rate 2a. What is the ratio of mass m1 to mass m2? Hints: 1. First, set F=m1*a 2. Then, set 3F=m2*2a 3. Solve each of these equations for m1 and m2, respectively. 4. Then, to get the ratio of m1 to m2, just take m1/m2, and replace m1 and m2 with your answers to step #3.

But if then Harry and Dumbledore would be traveling, but at a very high velocity?

2. Done 4. Done

Didn't get nearly the progress made this weekend that I had hoped, as I'm definitely bogging down in the Regents Kinematics Content section of the website... taking some time to organize how best to deliver the material over an online medium. What seems so straightforward to teach in person, where you can fairly easily "hop around" to various topics to pull it all together, can get quite dicey when putting it in writing. :banghead) I also want to make sure I include plenty of sample problems, as I believe what will set APlusPhysics apart is its worked out problems. And of course, as you move into acceleration and then into dt, vt, and at graphs, graphics and animations can make all the difference. Guess I'm gonna have to brush up on these in the next couple weeks. In the meantime, though, as I have had a few 20 and 30minute free spells over the weekend, I've cleaned up some of the Forum settings, fixed up the Physics In Action Podcast content page, added the Projects > Speaker competition page, and converted my old Momentum WebQuest into the APlusPhysics template and added that under Educators > Activities. Next Steps: Continue Regents content development Create a formal lab report guidelines page (not sure where best to place this yet...) Get the "About" pages started Add rating system to the APlusPhysics Forums Test out the Blogging System for use as a simple course management system

[ATTACH=CONFIG]45[/ATTACH]From NPR: Link Here A few years ago, physicist Jeff Harvey invited Eduard Antonyan to a game of poker at a friend's house. Antonyan was a graduate student of Harvey's at the time, in the physics department at the University of Chicago. "I invited Eduard to play because we're always looking for new victims," Harvey tells NPR's Guy Raz. "But it didn't exactly work out that well." It turned out Antonyan was pretty good. "He took my money," Harvey says. "We didn't invite him back after that." Antonyan would eventually find other ways to play. Today he plays online, where he says he hauled in $10,000 on his best night. But what's interesting about Antonyan and Harvey is not how much they win — but why. Big Game Theory Science writer Jennifer Ouellette (who was interviewed last year for the Physics In Action Podcast!) is married to a physicist herself. Like Harvey and Antonyan, her husband also plays poker — a connection that piqued her interest. "At first I thought it was just a fluke," she tells Raz. But a little research revealed there are a lot of pokerplaying physicists, some of whom are pretty serious about the game. Physicist Michael Binger placed third in the 2006 World Series of Poker, winning $4 million. Two others, Michael Piper and Liv Boeree, competed last spring in a tournament in San Remo, Italy. Piper placed fourth, and Boeree won, racking up $1.6 million. Ouelette's husband, CalTech cosmologist Sean Carroll, entered a Chicago tournament in 2004 and, to his surprise, met three other pokerplaying physicists, including Harvey. In a recent article for Discover Magazine, Ouellette says one reason so many physicists are playing poker — and playing well — is that their brains are particularly attuned to thinking about probability, statistics and modeling. In physics, those things are crucial. And in poker, they just might give you a leg up. "I mean — when you think about it — they build models of the world," Ouellette says of physicists. When her husband plays, she says, he's trying to model his opponents based on their style of play — from betting patterns to "tells." "He's using that to build a model — to predict them a little bit better." That model, Ouellette says, can help physicists make better decisions about their own play. Not Just Counting Cards Ouellette says that one reason poker is so intensely complicated — and thus suited for physicists — is that it's largely a game of probability. "If you think about throwing one die, for example, you've got six possible outcomes," she says. But add a second die? Suddenly your probabilities are a lot more varied: 36 possible outcomes to be exact. Now take your model 52 cards, Ouellette says, and you've got more than 2.5 million possible fivecard combinations. And if you're playing Texas Hold 'Em — which uses seven cards? Around 133 million combinations. "The numbers get really big really fast," Ouellette says. Of course, there's no human brain capable of crunching those numbers mentally. But Ouellette says training in physics does help a player think about complex probability models in a deeper and more realistic way. Harvey, whose specialty is string theory, says there's another advantage that physicists might hold over their opponents. It's called "tilt" and refers to the way players let emotions get the better of them when things are going badly. "In physics, you have to be able to sit down and work on a long complicated calculation that may often take you weeks or even a month," he says. And sometimes, physicists have to throw that work out and start again when they realize their calculations are incorrect. "Being able to deal with extended periods of bad luck or things not going well is something that's also required to be a physicist," Harvey says. "I think there is an element of emotional control that perhaps physicists learn." Math Folds, Physics Holds It's been mathematicians, historically, who've held sway at the poker table, Ouellette says. John von Neumann, the famous Hungarian mathematician and founder of game theory, based his work on twohanded poker. "He was fascinated by the art of the bluff," Ouellette says. "And he founded game theory based on 'What do I think the other man thinks that I'm going to do?' " When it comes to physics, she says, mathematicians have done a lot of the groundwork. "Physicists are kind of catching up, and realizing that there's a lot of interesting theory at play here." And even though you may not have heard of most of the physicists playing poker today — there's one you probably have. "Einstein actually enjoyed gambling," Ouellette says. As legend as it, the father of relativity loved to play craps and blackjack in Las Vegas, where he once met Nick the Greek, one of the greatest poker players of all time. "Nick introduced him to all his gambling buddies — knowing that they wouldn't know who Einstein was — as 'Little Al from Princeton, controls a lot of the action around Jersey.' "

Some thoughts: Start off with conservation of energy to relate the velocities, so that: Note that this is a Pythagorean Theorem relationship, therefore they must form a right triangle, and the angles between and must be 90°. You can use this to determine your angles after the collision. A diagram here is helpful. Next, use conservation of momentum in the xdirection to relate all xcomponent velocities before and after the collision: You can also use conservation of momentum in the ydirection in the same way: Solve these equations simultaneously to obtain and . Reminder: Your calculator must be in degree mode! :egg)

Hi Folks, If you don't get an option to upload an image file from your computer when you attempt to insert an image into your posts, you can enable this in the following way: Go to Settings > General Settings and set Message Editor Interface to "Show Enhanced (WYSIWYG) Editor." Next time you attempt to upload an image by clicking on the "Insert Image" button ([ATTACH=CONFIG]41[/ATTACH]), you should be given the option of uploading a file directly!

After several weeks of design as well as months of selftraining courses, I have the first pass at an entire page for the content section complete! It took some work in Flash Catalyst, Illustrator, Dreamweaver, and MathType to put it all together, but I think it's looking swell for attempt #1. Check it out: http://www.aplusphysics.com/courses/regents/mathreview/reg_mathreview.html. :wave)

Awesome! Were they impressed? :einstein)
Terms of Use
The pages of APlusPhysics.com, Physics in Action podcasts, and other online media at this site are made available as a service to physics students, instructors, and others. Their use is encouraged and is free of charge. Teachers who wish to use materials either in a classroom demonstration format or as part of an interactive activity/lesson are granted permission (and encouraged) to do so. Linking to information on this site is allowed and encouraged, but content from APlusPhysics may not be made available elsewhere on the Internet without the author's written permission.
Copyright Notice
APlusPhysics.com, Silly Beagle Productions and Physics In Action materials are copyright protected and the author restricts their use to online usage through a live internet connection. Any downloading of files to other storage devices (hard drives, web servers, school servers, CDs, etc.) with the exception of Physics In Action podcast episodes is prohibited. The use of images, text and animations in other projects (including nonprofit endeavors) is also prohibited. Requests for permission to use such material on other projects may be submitted in writing to info@aplusphysics.com. Licensing of the content of APlusPhysics.com for other uses may be considered in the future.