Recent content by MeMoses

  1. M

    Probability - expectation and variance from a coin toss

    Homework Statement A coin is flipped repeatedly with probability p of landing on heads each flip. Calculate the average <n> and the variance \sigma^2 = <n^2> - <n>^2 of the attempt n at which heads appears for the first time. Homework Equations \sigma^2 = <n^2> - <n>^2 The...
  2. M

    Potential generated by an ionized plasma between two plates

    Yea that really simplifies things from how I was approaching it. So F_{mag} = F_{electric} EQ=Q(v \times B) E=-vB so then V = hBv
  3. M

    Potential generated by an ionized plasma between two plates

    Homework Statement An ionized plasma flows with a velocity v in the z direction, though a rectangular pipe with x, y, z dimensions of w, h, l respectively. The walls at x=\pm w/2 are insulating while the walls at y=\pm h/2 are conducting. Lastly there is a magnetic field B in the x...
  4. M

    Finding parallel resistance of an RLC circuit at resonance from V

    Homework Statement I need to be able to determine the equivalent parallel resistance of an RLC parallel circuit, from a measured voltage when the circuit is at resonance. Homework Equations The Attempt at a Solution I know the values of the circuit element, but I'm not sure how...
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    How is the Minimum Value of a Multivariable Function Determined in a Quadrant?

    Homework Statement f(x,y) = x^3 - 3x^2 - 6xy + 7y + y^2, x>=0, y>=0 i) Explain why f attains its minimum value on the quadrant. ii) Find the critical points and classify them Homework Equations df/dx = 3x^2 - 6x -6y df/dy = -6x + 7 +2y d^2f/dx^2 = 6x-6 d^2f/dy^2 = 2 d^2f/(dxdy) =...
  6. M

    Physical Chemistry Problem, Evacuated tube - where does reaction take place?

    Homework Statement Two balls, one soaked in concentrated HCl and the other in NH4OH are placed at the left and right ends of a 1m long evacuated glass tube, respectively. HCl and ammonia vaporize and travel down the tube, reacting to form a white ring where they meet. Where does the ring form...
  7. M

    Differential Equation, nonlinear, nonexact

    Homework Statement \frac{dy}{dx}=\frac{2y - x + 7}{4x - 3y -18} Homework Equations The Attempt at a Solution I tried using v = y/x and got nothing. Same goes for trying to find an integrating factor to make the equation exact. I am given a hint, Find h and k so that the...
  8. M

    Maximum speed of overdamped oscillator without crossing origin

    Sorry i type that from my phone. The lim x(t) as t approaches infinity is 0, it will always go to 0 eventually but how do I know if it crosses the origin or not and how can I find the initial speed using what you told me? Edit: also how can I solve the coefficients?
  9. M

    Maximum speed of overdamped oscillator without crossing origin

    I get x(t) = Ae**((-g-z)t) + Be(-(g-z)t) with z=sqrt(g**2 - w**2). At t=0 I get x0 = A + B
  10. M

    Maximum speed of overdamped oscillator without crossing origin

    Edit: My idea made no sense. So how do find this maximum v0?
  11. M

    Maximum speed of overdamped oscillator without crossing origin

    Homework Statement An overdamped oscillator with natural frequency w and damping coefficient g starts out at postion x0 > 0. What is the maximum initial speed towards the origin it can have without crossing the origin? Homework Equations x(t) for overdamped oscillator The Attempt at...
  12. M

    Effects of Removing a Spring on Oscillating Mass: Analysis and Amplitude Changes

    I am an idiot. So for amplitude I get d/2*sqrt(7). I don't know why I added a sqrt(3) as it came from nowhere so ignore that and you should get this.
  13. M

    Effects of Removing a Spring on Oscillating Mass: Analysis and Amplitude Changes

    And fixing that mistake I get A in the 1 spring to equal d/2*sqrt(6). I then get amplitude = sqrt(6*d**2 / 4 + d/2*sqrt(3))
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