Recent content by dawin

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    EMA: Measuring Material Aging with Experimental Modal Analysis

    When I was in college there was a modal research group which was looking to correlate FRFs to structural damage, which you could argue could include effects of aging. In general, you're assuming that damage affects local stiffnesses which in turn affect your final modal response. I think what...
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    How much does it cost to produce a carbon-fiber bicycle frame

    As someone has mentioned, you need a mold. However, how you plan to make the carbon parts will affect your mold design. Also, do you plan to have just one piece, or will you be joining them? You can make carbon fiber tubes pretty easily. If you're hand-laying up woven fabric, at this point the...
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    Finite difference method to solve first-order, multivariable

    What are the boundary conditions for this particular problem, and why are you trying to use an explicit method? Is there a particular reason? I don't see your explicit formulation, only a first-order approximation to the partial derivative. Depending what information they give you, I'd think...
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    Applied Physics Differential Equations Problems/Solutions book?

    Well that was an easy sell, haha. I think between the ones I listed, the book you gave, and the Irodov book (General Problems in Physics)--the last one has quite a few solution sources online too (that go into more detail if needed--I should have plenty of work to do.
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    Applied Physics Differential Equations Problems/Solutions book?

    That looks like a good book. I like that they go through the solution in some detail instead of essentially going, "Here." I'll pick this up and probably combine with some of the other books I've found. Thanks! For me, I'd like to improve my ability to "think" in DEs -- I watch some people...
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    Applied Physics Differential Equations Problems/Solutions book?

    Thanks for the comment. I do have this book and agree it's well laid out. Now I'm looking to stash some practice problem books so I can get a better grasp on applying the material I'm learning. After all, practice makes perfect. Or, perfect practice makes perfect. However it goes.
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    Applied Physics Differential Equations Problems/Solutions book?

    I want to develop my feel for reading/interpreting differential equations, particularly in Physics applications (for developing models and understanding ones that others have developed). Are there any good books out there that present problems that require deriving governing differential...
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    Best portable device for math PDF files?

    iBooks is plenty capable of reading PDFs, and storing them in the library. Granted, I've been experiencing a bug where all of mine have disappeared, but admittedly haven't looked into it too much. Worked fine up until that point, and on new PDFs, though.
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    Earth's rotation having effect on sub-orbital trajectory

    I get 1.84 * 106 km (GM/(R\omega)^2)... 1.84 * 108 seems like a large number... 25% further than the distance between the Earth and sun.
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    Get to the bottom of your rocket problem yet!?

    Get to the bottom of your rocket problem yet!?
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    Final velocity of a rocket launching to space

    I've never played the game, so I can't really speak to how it works out. Where did you see the physics engine? Why not identify some parameters and come up with an empirical solution from some mini design of experiments!
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    Final velocity of a rocket launching to space

    Well it looks like you have just the force balance there. Have you considered looking at conservation of momentum too? You have an \dot{m} term in there... if the "rocket" starts out with mass m, and loses a bit of propellant going in the opposite direction (staying consistent with your model's...
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    Final velocity of a rocket launching to space

    Is there a reason you can't make assumptions for the one of the terms on the right hand side? For one, it wouldn't be unreasonable to assume F_T is a function of \dot{m}. But not sure if how you laid it out is just how you wanted to approach the problem.
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    Natural position of a string wrapping around a cone

    I've had a problem I encountered at work some time ago and took a personal interest in. I never did end up solving it, but I've recently looked at it again. It goes like this: You have an axisymmetric part, such as a cone, and it's positioned such that its central axis is coincident and...
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    Mathematically modelling a mechanical system

    I don't understand what you mean by needing sampling points, etc. to achieve an accurate description of this system. Could you explain more clearly? My understanding is that you have some arbitrary gear system that you'd like to mathematically model so that at any point in time, call it t...
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