Recent content by FlorenceC

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    Use the uncertainty principle for momentum vs. position to e

    Homework Statement Please see the attachment for a better picture The energy of an electron in a hydrogen atom is: E = p^2/2m - αe2/r; where p is the momentum, r the orbital radius, me the electron mass, e the electron charge, and α the Coulomb constant. Use the uncertainty principle for...
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    What Is the Kinetic Energy of a Proton at 1/4 the Speed of Light?

    Homework Statement Calculate the deBroglie wavelength of a proton moving at 1/4 the speed of light. How does the kinetic energy of this proton compare to its p^2 /2m? What does p^2 / 2m anyway conceptually (isn't it one of the triangle thingies in the lower version of E=mc^2)? Homework...
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    How do I prove |cosa - cosb| <= |a-b|?

    nvm. I figured it out, it's a subtle trick with MVT
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    How do I prove |cosa - cosb| <= |a-b|?

    Homework Statement I have no idea how to approach this question. Homework EquationsThe Attempt at a Solution I suppose ∫ |cosa - cosb| < = |a-b| sinb-sina <= b^2/2 - a^2/2 but now what do I do?
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    Why Does Changing Variables in an Integral Preserve Equality?

    Okay, so -∫1 f(u) du = ∫01f(u) du. but how do i relate this to ∫f(x)?
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    Why Does Changing Variables in an Integral Preserve Equality?

    Homework Statement prove that the ∫01 f(x) = ∫01f(1-x) Homework EquationsThe Attempt at a Solution I got all the way to ∫01-f(u) du where u = 1-x but I don;t know how to prove it.
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    How to find phi in simple harmonic motion

    Yes but I don't know phi? How do I know x(t)?
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    How to find phi in simple harmonic motion

    Given a position vs time graph of simple harmonic motion of an object and using the equation x(t) = xo = A sin (ωt +Φ), how am I supposed to find Φ? I can easily find A and the period (T). I also know T = 2 pi / ω, so I can find ω. But I don't know x(t) and t. I tried finding random points in...
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    Transformation of Matrix onto plane

    Find the matrix for the transformation that projects each point in R3 (3-D) perpendicularly onto the plane 7x + y + 3z = 0 . The attempt at a solution is attached for question 1 (actually instructor's solution) I kind of understand it but ... why is n <dot> v = equation of the plane? Does v...
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    Linear Algebra Matrix Transformation to plane

    Find the matrix for the transformation that projects each point in R3 (3-D) perpendicularly onto the plane 7x + y + 3z = 0 . The attempt at a solution is attached for question 1 (actually instructor's solution) I kind of understand it but ... why is n <dot> v = equation of the plane? Does v...
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    Prove limit x approaches 0 of a rational function = ratio of derivatives

    Yes. but how does mvt apply? we didn't learn lhopitals rule yet.
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    Prove limit x approaches 0 of a rational function = ratio of derivatives

    1. The problem statement, all variables and given/known dat If f and g are differentiable functions with f(O) = g(0) = 0 and g'(O) not equal 0, show that lim f(x) = f'(0) x->0 g(x) g'(0) The Attempt at a Solution I know that lim as x→a f(a) = f(a) if function is continuous. since its...
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    Find the maximum of 'arbitrary power' function

    If a and b are positive numbers, find the maximum value of f(x)=x^a(2-x)^b D={0<=x<=2} attempt of solution I did this question more intuitively. So I first differentiated and found it to be axa-1(2-x)b + xa (2-x)bb-1 and I figured it will only be <0 when x>=2 and b is odd, so it will be >0 on...
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    Prelab rotational motion question

    There is an experimental set up that looks like the attitude file. 1) for mass hanging down the pulley write Newton's second law 2)since the sensor measures α find substitute a with a variable containing α 3) for the drum (horizontal pulley) find another equation for torque other than τ = Iα 4)...
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    Truss Analysis using joints method 2D analysis

    Given a warren truss, where the load is 2kN/m so the weight per joint is 10kN, since the ends are supported by ground not truss, can anyone please verify my way of solving for the tension and compression at point B. See attachment Your help is greatly appreciated. So I figured out that AB is...
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