Ondrej, Great comments! How are you!? We need to get a beer next time you are coming through -- do you have a regular schedule, maybe Google Calendar that we can share?
> 1) How did you create the drawing in the pdf? I used TikZ. I looked into PStricks, which is very powerful, but it seems like TikZ has a bit nicer design and is a bit higher level. But other options include Inkscape, which can export pstricks/tikz code to be included in your latex code. Another cool online tool is: http://www.geogebra.org/cms/ it will also let you export those formats, but gives you a nice gui and still lets you easily change the exact values of all the coordinates, should you want to be precise. > 2) We did this exact example in our undergrad mechanics course at my > university using a Lagrangian to derive the equations of motion. I > wonder if i can redo it, I would love to put this and similar examples > into my notes at theoretical-physics.net. Also with your solution, to > show that one can derive the equations of motion in another way. Yeah, Lagrange's is the way to go, I didn't do that approach for the solution because I figured F=ma would be the "simplest" and least likely to raise flags about "fancy math" being used. But when F = dp/dt = ma is not allowed.... I'm not really sure what technique to use.... > 3) Can pydy derive the equation of motion? Definitely, although it is almost overkill :) > 4) Feynman would of course never use your systematic approach, but > rather use some trick to find the solution in 2 lines One of the perks of being Feynman, I suppose :) > 5) Point 4) is precisely why I don't like Feynman's approach to > physics as a way to learn and do physical problems, but I like it as > an amusement and to get new physical insight, *after* I have been > able to solve the problem using a systematic approach. This is also > the motivation behind theoretical-physics.net, to *only* use > systematic approach and reject all "tricks". Yeah, whenever I hear the word "trick", I get a little uneasy. Cass said she might remember having seen a "trick" for this problem, but couldn't find it or remember it. I don't want to memorize a bunch of "tricks", I want to know a few key principles and concepts and be able to apply them to lots of different problems. I agree though, after you understand something, it is nice to see the shortcut. > 6) If anyone finds the trick to solve the problem, I would be interested. I'll let you know. I sent it out to a bunch of physicists and engineers here at UCD and haven't heard any ideas from any of them. > Ondrej > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > -- "Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety." -- Benjamin Franklin, Historical Review of Pennsylvania, 1759 -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
