Recent content by arizonian

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    Is Balancing Work and Electrical Engineering Studies Feasible?

    Stay the course and it will be worth it. I struggled with CalcII and Diff. Eq., got lost in Elect. & Mag., found help in the Phys. lab when I really needed it, and graduated yesterday from the Univ. of Arizona. The biggest hurdle I had to overcome was asking for help when I really needed it. Bill
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    I'm struggling in first year engineering

    Don't worry, you are not alone. I just turned fifty and "should" graduate in May. Math is still hard, but the difference is I am more accustomed to it and less fearful. I will be taking a course in vibrations and I am dreading having to re-learn Fourier series, but I know the professor and what...
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    Is Computer Modeling Sufficient for Testing Bridge Designs?

    Thanks, Clausius2 and rdt2. I still think I am in the field, and any plastic yield is significant. Bill
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    Linear ODE Systems in Numerical Methods.

    Any body care to comment? Bill
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    Linear ODE Systems in Numerical Methods.

    I feel so embarrased asking this question, but this is the place to get answers. I have a 2nd order ODE with a forcing function that needs to be manipulated and put into a matrix for a numerical method solution, ie Matlab. My question is: Is the matrix composed of a particular solution in the...
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    Is Computer Modeling Sufficient for Testing Bridge Designs?

    Hello. I am in my senior year in mechanical engineering at the University of Arizona. I have spent the previous 25+ years hanging iron, installing mining equipment, building oilfield trucks and rigs, etc. I don't mean to hijack this thread, but a couple of thoughts have crossed my mind when...
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    MATLAB Solving ODEs in Matlab without ODE45 or Built-In Functions

    Maybe my understanding of differential equations with boundaries is suspect. The code does run, the incrementation is taking place like it should. I did compute the second term and it is correct. The third term is correct, and the fourth, and the fifth. I have egg on my face. Bill
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    MATLAB Solving ODEs in Matlab without ODE45 or Built-In Functions

    Got past the first problem, but I am stuck on another problem. The indices don't seem to be working like I think they should. The equations of interest from the homework assigned: dy/dx = -2y+5*exp(-x) % (y1) dz/dx = (-y*z^2)/2 % (y2) I am...
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    Help in understanding: Temperature, Heat, and Expansion

    On problem # 2, set up a control volume, and calculate the energy in minus the energy out, which is zero. 20 degrees Centigrade is 20 degress centigrade, not 1.76. For problem #3, you need to know the heat of fusion. When ice melts, it takes heat from the environment, which is the water. How...
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    MATLAB Solving ODEs in Matlab without ODE45 or Built-In Functions

    I am having trouble with some Matlab code that I am writing. I am attempting to solve ODE writing my own code, per the Professor. That means I cannot use ODE45 or other built-in functions. My problem: Oiler, a play on Euler, calls another function, FX, that contains the two equations that I...
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    What is the mass of the meter stick?

    Pick a point, any point, and sum moments to zero. Define your variables; mass of stick and coins, ms and mc; forces, a, b, and g. Solve for ms.
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    Other Becoming an Engineer: Considerations and Personal Experiences

    A mechanical engineer is a mechanic with the tools in his head. He may or may not be good with a wrench or torch, but he will understand what has to be done and what not to do. I am 49 and in my last year(I hope) of ME at the U of Arizona, and I wonder why I did not do this long ago. The...
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    Solving Simpson's 3/8 Rule Problems with Matlab SV7

    kakarukeys, Thank you, you are spot on. Bill
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    Solving Simpson's 3/8 Rule Problems with Matlab SV7

    I am having problems in Numerical Methods with Simpson's 3/8 rule of integration. Of course, this is computer driven. The code that I have written for Matlab (SV7) goes as such: 1) function simpson38(f,n,a,b) 2) h = (b-a)/n; 3) x = a; 4) sum = f(x); 5) for i = 1:3:(n-3) 6) x = x + h...
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