Recent content by eptheta

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    How to graph a sin function with respect to it's limits and x intercepts

    It's actually part what periodic functions are. for a periodic function g(x): g(x+P)=g(x) where P is the period. So your function f(x)=sin(x) is as good as f(x)=sin (x \pm n\pi) n=0,1,2... so x=sin^{-1}(y) \pm n\pi now go ahead and put y=0 to get all your x intercepts.
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    Limits in the complex vectorspace

    Hi, I am trying to prove that a limit exists at a point using the epsilon delta definition in the complex plane, but I can't seem to reach a conclusion. Here's what I have been trying to get at: \lim_{z\to z_o} z^2+c = {z_o}^2 +c |z^2+c-{z_o}^2-c|<\epsilon \ whenever\ 0<|z-z_o|<\delta...
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    How Does Angular Velocity Influence the Orientation of a Spinning Hoop?

    I didn't integrate anything and got the same answer as you. I used L=L_s cos(\beta) \hat{j} + L_s sin(\beta) (-\hat{r}) \tau=RT sin(\frac{\pi}{2} - \alpha + \beta) \hat{\theta} (got T from F=ma in x and y) then used \frac{dL}{dt}=\tau and got \beta=\frac{2g}{R\omega^2} Can anyone else...
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    Quick question about the direction of angular momentum.

    When talking about the net angular momentum about where must one calculate the component due to Ω ? Just wanted to confirm my thoughts: Will the expression be L_{net}=MR^2\omega \hat{r} + \frac{1}{2}MR^2\Omega \hat{k} Where MR^2 represents the moment of inertia about the spin axis in the...
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    Analyzing Torque on a Racecar: Solving for Normal Reactions on a Circular Track

    Ah, that's right. I kept thinking that C was acting downwards even though I mentioned that it was in \hat{r} in my previous post. Indeed, it works out fine. Thanks a lot.
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    Analyzing Torque on a Racecar: Solving for Normal Reactions on a Circular Track

    Doc, How is point P accelerating any different than the CM is ? From what i can see, the CM is moving with the same acceleration as point P at all times during this motion. And if there is no need to get into an accelerating reference frame when analyzing the CM motion, why is there a need to...
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    Analyzing Torque on a Racecar: Solving for Normal Reactions on a Circular Track

    The problem statement A race-car is driving on a circular track, and above a particular speed, the race-car may flip over towards the outside track (inward wheels lift). Frictional force is present. The distance of the center of mass from the ground is L, the distance between the wheels is 2d...
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    Continuity of a two variable function

    I have a function in x and y, and I was trying to figure out if it was continuous or not. f(x,y)=\frac{x^2-y^2}{(x^2+y^2)^2} As far as I know, the only problematic point in the domain is (x,y)=(0,0) so I tried to use the \epsilon,\delta definition. My proposed limit at (0,0) being 0...
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    Small oscillations about equilibrium

    Actually, the rod I'm talking about is also vertical. Here's an image: The rod is pivoted at O and torque calculations were done about this point. As far as I can see, the weight still contributes a cosθ component to torque. The equation simplifies to \ddot{\theta} + \frac{15k}{4m}\theta...
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    Small oscillations about equilibrium

    I know this is 2 years old, but I did the same sum just now and got almost exactly what the OP has, except for one thing: \tau_g=\vec{r} \times \vec {mg} =\frac{L}{2}\hat{r} \times mg (-\hat{j}) =\frac{mgL}{2}([cos\theta\hat{i} +sin\theta\hat{j}] \times -\hat{j})...
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    How big should sugar crystals get?

    While I am back in this thread, I may as well re-ask my original question: Is there a physical limitation to the size of a crystal grown by suspension in a supersaturated solution ? I mean theoretically the crystal should grow indefinitely as long as the concentration is maintained throughout...
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    How big should sugar crystals get?

    I don't even think sucrose is soluble in alcohol. This reminds me of those salt crystal gardens. Several people suggest using ammonia mixed in water as a solvent... Maybe a mixture of alcohol and water (and if so, then ammonia and water) could help keep the solution supersaturated if it does...
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    How big should sugar crystals get?

    Wow, that's big ! Tell me, did you initially plan to grow it uniformly (i.e in its standard crystal configuration) but it went haywire? Or was it your intention to grow a crystal cluster ? I've tried to grow sucrose crystals too but after a certain point(size/volume) they stopped growing and...
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