Recent content by johnnyTransform

  1. J

    Schools A third year physics university student

    Yes, in the past I've felt as if there's so much course material to cover in some classes I've taken that more "abstract" learning objectives like knowledge of full derivations and proofs are brushed aside for a more operational knowledge of the subject (at least, this is my experience in...
  2. J

    Classical Mechanics

    Firstly, the rigor and scope of the class is up to your particular professor, so this question is hard to answer. However, the best general advice I could give would be to not worry too much about the mathematics of a first course in CM. Like the above poster said, you'll probably just run...
  3. J

    I don't understand physics

    I'll have to agree with axmls -- practice is key. Anybody can plug-and-chug energy balances, but the true key to excelling at physics is understanding the equations in not just numbers, but also words. I'd encourage you to first make sure you spend plenty of time understanding the equations...
  4. J

    How to create a matrix with variables?

    I'm not entirely sure that you can use symbolic variables in a MATLAB matrix like that. If the variable act changes value over time, I'd create a loop with the number of time steps desired and calculate the value of act during each iteration, and then in that same iteration manually update the...
  5. J

    Programs Should I still pursue a physics major? please help!

    Well, first, congrats on your choice to (at least initially) follow your passion and pursue physics. However, we should tackle both problems separately. Having difficulty with the problems now is natural, as a university physics program is expected to be more rigorous than a high school...
  6. J

    Schools Grad School with a BS in Mechanical Engineering Technology

    Not the same situation, but perhaps somewhat similar. I had a less-than-stellar high school performance for a good chunk of my high school career, but came to my senses (or whatever you'd like to call it) down the line, and realized that I was interested in engineering and applied to colleges...
  7. J

    Programs Majoring in pure mathematics

    Many pure Math majors I know of who didn't perform "above average" with projects and/or research to show had some trouble finding work right out of school, which is an anecdote to consider. Pure math is incredibly abstract, but is a great basis for just about anything -- applied mathematics...
  8. J

    Course selection for next semester

    Do you have a particular concentration within Mechanical in mind? 1) would be advised for one looking into thermofluids, 2) for one interested in materials, etc.. However, if you aren't sure of a concentration yet, 3) is almost certainly the most likely of the options to increase your chances...
  9. J

    Poor performance in first and second year physics...

    I'd definitely take the time to brush up on some of the earlier physics. I feel as if the most important lessons gained from Physics I/II aren't necessarily the specifics of the subject materials (though obviously the specifics are not to be neglected -- for example, second law analysis is...
  10. J

    Decision between electives

    Short and to the point--very good! Thanks. I went with the Heat Transfer class =)
  11. J

    Decision between electives

    Hi all, I'm a ME graduate student concentrating in fluids and I'm trying to decide between two electives. The two I'm looking at are Nonlinear Control Systems or Advanced Heat Transfer. Nonlinear controls looks interesting, but I'm not sure how it could tie in with fluids...as opposed to heat...
  12. J

    MATLAB 3D Diffusion Equation in MATLAB

    Update: I think I may have figured out my universal decay problem. My solutions now display heat flux, and not just a static decay to zero. I'll explain what I'm thinking might be the trick for people who have similar problems in the future: Starting with the 3D Diffsuion Eq...
  13. J

    Solving this "simple" PDE

    Hi guys, I've distilled the 3D Diffusion Equation into the following PDE using Fourier spectral techniques: ∂C(m,n,p,t)/∂t + k(p^2+m^2+n^2)C(m,n,p,t)=0, where C is the Fourier coefficient of the 3D Fourier transform, {m,n,p} are the spatial frequencies, and t is time. I've tried using a...
  14. J

    MATLAB 3D Diffusion Equation in MATLAB

    Just as a conjecture for those who are curious, I think it may have to do with the fact that I'm forwarding my Fourier coefficients in time using an explicit scheme. However, it's still an open question EDIT: Sorry, I couldn't find the option to edit my original post. Not trying to bump this...
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