Recent content by papasmurf

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    Quick question regarding some algebra?

    The gain of an internally compensated op amp may be expressed by Equation 1) A(s) = A0 / ( 1 + s/\omegab) where \omegab is the 3dB frequency or "break frequency" and A0 is the dc gain. Plugging in s=j\omega and \omega = 2*pi*f gives Equation 2) A= A0 / (1 + j*f / fb) where fb is still...
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    Determining if a System is Time-Invariant and/or Linear

    Im following you until you talk about making the delay prior to inputting the signal. Let me see if I am understanding. It looks to me like, unless you pick a d that delays it by 2*pi*k where k is an interger, it won't produce the same output?
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    Determining if a System is Time-Invariant and/or Linear

    Homework Statement For each of the following systems, determine whether or not the system is Time-Invariant, Linear, and causal. a.) y[n] = x[n]cos(0.2*pi*n) there are more but if I can figure this out I should be able to get the others Homework Equations Time Invariant ---> if x[n]...
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    Semiconductors: Find maximum Operating temp.

    How do I know if I can neglect NA? In a lot of the example problems in the book, it always talks about neglecting one thing or another because it small, but I don't see where it says what "small" means, or how you know something is small based on another value.
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    Semiconductors: Find maximum Operating temp.

    Homework Statement "A GaAs device is doped with a donor concentration of 3x10^15 cm^-3.For the device to operate properly, the intrinsic carrier concentration must remain less than 5% of the total electron concentration. What is the maximum temperature that the device can operate?"Homework...
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    Statics Question (Using Modulus of Rigidity)

    I keep getting an answer that is off by fractions of a millimeter. I can not figure out what I am doing/not doing that keeps giving me a wrong answer.
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    Statics Question (Using Modulus of Rigidity)

    Also, should the h value be the height of the layer only or should it go from the base to the top of the layer I am looking at? For example if I am looking at the first layer where G=0.1MPa, would my h be simply w2 [mm] or would it be w2+2 [mm]?
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    Statics Question (Using Modulus of Rigidity)

    I'm getting closer to the correct answer. First I set V/A, where V is the internal shear force and A is the area of the cross section where the shear force is acting, equal to G*\gamma, where G is the modulus of rigidity and gamma is the shear strain. I rewrote gamma as pi/2 - θ, where...
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    Statics Question (Using Modulus of Rigidity)

    Am I correct in assuming the shear force will be the same at all the various layers?
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    Statics Question (Using Modulus of Rigidity)

    Homework Statement Find the displacement (mm) in the horizontal direction of point A due to the force, P. P=100kN w1=19mm w2=15mm Homework Equations \tau = G * \gamma \tau = Shear stress = P / A \gamma = Shear strain = (pi / 2) - \alpha The Attempt at a Solution I haven't...
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    Statics - Mechanics of Materials, check my work please?

    Sorry for no clarifying, both "legs" if you will are connected by pins so there are vertical and horizontal force components. Taking that into account I was able to figure out the pin length to be about 4.2 mm. Thanks guys.
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    Statics - Mechanics of Materials, check my work please?

    Could someone please check this for me? I attached a rough free body diagram of the whole frame. Any help is appreciated. Homework Statement The member ACF of the frame loaded as shown is connected to member BCD by means of a smooth peg and slot C with force P = 930 N at point D...
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    Statics Pulley FBD: Man's Weight on Cable and Pulley System

    Yes thank you so much! Just in time to get to class on time too! Thanks again Edit: Not important for class, but how did you figure Te to be 55 lbs. Just from solving the equations?
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