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  1. W

    Taking a year off

    So instead of one person relatively secure and one in trouble, we have, two in trouble? I think that's fairly counterproductive..
  2. W

    Deriving SHM equations

    No, I'm just using this as a tex notepad since no one was helping when I needed it. I'm good with all these. v = \lambda f \lambda = 4L v = 4L f f = \frac{v}{4L}
  3. W

    Deriving SHM equations

    Prove \left(\frac{ia - 1}{ia+1}\right)^{ib} = exp(-2b cot^{-1} a) and \sum_{n=1}^{N} \cos(2n-1) x = \frac{\sin 2n x}{2\sin x}}
  4. W

    Deriving SHM equations

    f = \frac{1}{2L}\sqrt{\frac{mg}{\mu}}
  5. W

    Deriving SHM equations

    \alpha ^{x+n} 2 dy + \left( \alpha ^3 x^2 - 3 \alpha ^n y) dx = 0
  6. W

    Deriving SHM equations

    iii) (challenging) now consider a wave made from a superposition of modes: \sum_{n=1}^{\infty} a_n\cos(\omega_n t)\sin(\frac{2\pi n}{L} x) calculate the total energy of this wave and comment on your answer. I get the KE and PE each to be 0 by the expression in post 3. We have...
  7. W

    Deriving SHM equations

    \frac{T}{2} \sum_{n=1}^{\infty} \sum_{m=1}^{\infty} a_n a_m\cos(\omega _n t) \cos(\omega_m t) {\left(\frac{2\pi}{L} x\right)}^2 n m \int_0^L \cos \left(\frac{2\pi n}{L} x\right) \cos\left(\frac{2\pi m}{L} x\right) dx
  8. W

    Deriving SHM equations

    The differential equation modelling this system is given by: m\Ddot{x} + 2\beta \dot{x} + \omega^2 x = 0 With \beta \ and \ \omega defined as \beta = \frac{b}{2m} \ and \ \omega = \sqrt{\frac{k}{m}} with m being mass, k the characteristic constant of the physical system, and b...
  9. W

    Deriving SHM equations

    Using Newton's 2nd Law for a damped oscillator: ma = -kx - \alpha x which is a second order linear DE. To solve it we use the trial integrating factor e^{\lambda x} [/tex] to come to the root equation mx^2 + \alpha x + k = 0 where we can find our two solutions to be r_{1} \ and...
  10. W

    Guess Where I Am

    You don't have to be mean.
  11. W

    Guess Where I Am

    She was pretty upset about that. It's not that bad out. Trib, tonight was your night but you lost it haha. We went to the drive in and almost watched a couple movies. Feel free to take us all out to dinner though o:) Smurf, pretty sure your hand doesn't have an STD. Both hands..
  12. W

    Guess Where I Am

    Shes in a hotel for the week, its working out pretty well.. and I say that in the least suggestive way possible. I'm on my way down there in a bit but don't think I'll be able to keep her company all day. We'll see. Any messages for her?
  13. W

    Guess Where I Am

    She's loving it, I unfortunately have to deal with it during the summer so I know how treturous it can be. I know that's spelled wrong.
  14. W

    Guess Where I Am

    It's a hookah bar/arabic restaraunt. She posted that at about 11:45 so it's not so late, the place is open til about 2ish but most restaurants are open til about midnight or so, unless its really chic.
  15. W

    What does one do when this feeling becomes overwhelming?

    Maybe incompetent wasn't the word but, sometimes I feel that this course of study requires an intellect and skill above that which I have. Granted, and I dn't mean to be full of myself, I'm a pretty smart kid, I still think the bar is still a little higher in terms of 'natural ability' than I...
  16. W

    What does one do when this feeling becomes overwhelming?

    I don't get it, and it was a more serious question..
  17. W

    Ths wrd hs n vwls

    I don't think 'nth' is a word. There are a lot of things in the dictionary now that arent really words. What makes something a word anyway?
  18. W

    What does one do when this feeling becomes overwhelming?

    What does one do when this feeling becomes overwhelming?
  19. W

    Final velocity of an electron

    With [itex] v_f = v_i + at [/tex] but you'd need to know how long you were in the field or atleast how far youve traveled in the field.
  20. W

    Dirction of fastest growth

    It is tangent to the surface at that point and I think that is what he is meaning, but when youre dotting D_{\theta}f(x,y) why did we get a negative cosine? You also forgot your j unit vector in the first expression.
  21. W

    Final velocity of an electron

    Then you would say that the total force is the electric force (F=qE) and follow Newtons second law (F=ma) and combining the two you can find the acceleration (while in the field).
  22. W

    Dirction of fastest growth

    Youre right. When you take a directional derivative what kind of product do you use (for the two vectors). One of these two is at a maximum when the angle is zero, that's the one you want to use. If you're still stuck, show the defining expression for a directional derivative.
  23. W

    Dirction of fastest growth

    At what angle is the growth greatest? Its got to do with the directional derivative and the gradient.
  24. W

    *bounces a story idea off the forum*

    Sounds like the basic idea of every other sci fi book.
  25. W

    Magnitude of the recoil velocity of the nucleus

    Before the explosion the particle is at rest. What is its momentum? No external forces means momentum is conserved.
  26. W

    Simple force question

    You have a force and a mass, you can find teh acceleration using Newton's 2nd law.
  27. W

    Magnitude of the recoil velocity of the nucleus

    Conservation of momentum theory says that the net momentum stays constant if there are no external forces acting. Are there any external forces? What was the initial momentum?
  28. W

    Finding center of mass of a picture

    Find the CoM in each direction seperately. Meaning stack all the blocks so that you only have one direction to deal with at a time. For example, imagine a figure with 3m on the left column, 2m in the middle column, and 1m on the right column (where m is the mass of one block). then find the...
  29. W

    Teenaged girls: The downfall of America

    You rag on a lot of people. You should stop criticizing the world so much.
  30. W

    Another problem

    The force of gravity is constant through out. Start with the position equation for simple harmonic motion.
  31. W

    Ionic or covalent- Please check

    Whats your reasoning, what's the difference between both?
  32. W

    For my sanity

    You don't need to talk to me to do that. And she's not my girlfriend.
  33. W

    AP Physics problem help - centripetal motion

    What is the net force acting on the bag? Redo your force diagram.
  34. W

    Walking up a hill physics work

    It says 10 VERTICAL meters higher, start = (x1,y), end = (x2,y+10)
  35. W

    Walking up a hill physics work

    d is the displacement against the force of gravity. Gravity acts in the vertical direction. I recommend you actually learn what the letters really mean instead of just plugging things into formulas.
  36. W

    Position vector

    The position vector points from the origin to the position of the particle. For your point it is < x , y , z > Positions that vary with time are expressed as functions of x y and z, and you get parametric functions: \vec{r}_t = < x(t) , y(t), z(t) >
  37. W

    Forming Linear Equations From Non-Linear Equations

    That would work provided you don't change the parameters in the { }.
  38. W

    Uniform acceleration

    This is an incorrect solution. He would never reach the car but be following it forever.
  39. W

    For my sanity

    either way is fine with me. i was hoping #1 would lead to #2 anyway.
  40. W

    Message in a bottle

    abby, wake up. you're dreaming again. keep talkin that much **** and you'll be the one needing biochemical supplements after trib and i are done with you.
  41. W

    For my sanity

    if you want you can get me and buddies drunk and party at your place after NNY :D
  42. W

    For my sanity

    we did that halloween, we need some new activities
  43. W

    For my sanity

    she's lying. she's not innocent at all.
  44. W

    For my sanity

    She's really upset. She's *****ing about you on AIM right now I'm going to native new yorker tonight, right by you
  45. W

    For my sanity

    I've driven by your house quite a few times Play there?
  46. W

    For my sanity

    Yeah you could get a crowd. It would be an upset for you though, unfortunately for you its the underdog that wins these kind of things. You live by Main Street Billiards?
  47. W

    For my sanity

    NE Scottsdale, you?
  48. W

    For my sanity

    Thats where I come in :D Just kidding..
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