Recent content by tentoes

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    Express the moment (torque) as a function of theta

    OK - I just submitted it using values for every 10 degree of theta and it accepted it - I think the point of that was that the value for the moment at P is actually higher when theta = 10 than theta = 0, and the relationship between moment and theta is NOT linear - which it sort of was when I...
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    Express the moment (torque) as a function of theta

    It has a graphing app but the values listed on the x-axis are theta = 0, 30, 60, 90 so those are the only ones I entered values for. There are tick marks for 10 degree increments of theta - if you think I did it right maybe I could try adding the values at those tick marks and see if it accepts...
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    Express the moment (torque) as a function of theta

    Here's the whole problem statement: "Determine the torque (moment) MP that the applied force F = 150 lb exerts on the pipe about point P as a function of θ . Plot this moment MP versus θ for 0∘≤θ≤90∘ . Consider positive moment as clockwise."
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    Express the moment (torque) as a function of theta

    Sorry - usually I can't copy information for the problems but this one allows it -
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    Express the moment (torque) as a function of theta

    Yeah - the wrench is horizontal, the P end of the wrench where the moment is applied is on the right, the force is applied in an upward direction on the left end of the wrench. Clockwise is positive for this problem, so I think no matter what the angle theta, a positive / clockwise moment will...
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    Express the moment (torque) as a function of theta

    Homework Statement The problem shows a wrench with a force being applied to one end. Rotation will occur around point P at the opposite end. The force is applied 43 inches to the left from P, and 6 inches above P. The angle theta is between the vertical axis at the end of the wrench (non-p...
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    Meaning of zero gradient vector with existant directional vector

    Unfortunately my Calc I teacher talked more about banking than calculus, so using the definition of derivatives is a little shaky - but, I do see how limit as h approaches zero of f(h,0)/h is 0/h = 0. And I do understand that you have to get the partial derivative that way, rather than just...
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    Meaning of zero gradient vector with existant directional vector

    The limit of the partial derivatives does not exist, even though I think they're defined (continuous) at (0,0), so I guess that's why f is not differentiable.
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    Meaning of zero gradient vector with existant directional vector

    yes, that was the point of saying y=rsin(t) and x=rcos(t) - somehow that proves that the limit is the same through all...things/lines going through that point. For some reason the limit of this substitution being equal to zero is conclusive, even though another substitution - say y=mx, is not...
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    Meaning of zero gradient vector with existant directional vector

    So the original function is not differentiable? It has a limit, and it equals that limit at (0,0) - doesn't that make it differentiable?
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    Meaning of zero gradient vector with existant directional vector

    What does it mean for the partial derivatives to "exist" near (0,0)? I think they exist. Are they continuous at (0,0)...I guess not? The function itself is defined and continuous because the limit from either direction equals zero, and the function at (0,0) equals zero, but the partial...
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    Meaning of zero gradient vector with existant directional vector

    There's no condition on the definition in the book, but another theorem says that f must be a differentiable function at (0,0), and because the limit of the function (when x=rcos(theta) and y=rsin(theta)) equals zero conclusively, the function is differentiable, so the directional derivative...
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    Meaning of zero gradient vector with existant directional vector

    I'm supposed to find the gradient vector of the function below at (0,0), and then use the dot product with the unit vector to find the directional derivative. Then find the directional derivative using the limit definition of a directional derivative, and explain why I get two different...
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    Concept question, linear momentum and mechanical energy

    When the mass is removed the total kinetic energy would be zero, but that doesn't imply (to me) that changing the mass won't change the overall kinetic energy. But I do see how potential energy is conserved - if it is at its original maximum amplitude when the pebble is removed, then 1/2*k*x^2...
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    Concept question, linear momentum and mechanical energy

    A box containing a pebble is attached to an ideal horizontal spring and is oscillating on a friction-free air table. When the box has reached its maximum distance from the equilibrium point, the pebble is suddenly lifted out vertically without disturbing the box. Will the following...
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