Recent content by Alex Santos

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    How Do You Calculate pH and [OH-] for a Mixed NH3 and NH4Cl Solution?

    Homework Statement [/B] NH3(aq) is a weak base with Kb = 1.8*10-5, Calculate [OH-] in a solution that is made by mixing togeather 500ml of 0.20M NH3(aq) and 500ml of 0.20M NH4CL(aq), what is the value of Ph?Homework Equations Henderson Hasselbalch: ph = Pka + log([conj.base/acid]) As well as...
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    Uniform beam reinforced with iron, how to approach?

    So I am starting to learn for the final exam a bit early and I am trying to do this problem with a uniform beam which is reinforced with iron inside. I know how to calculate this if it wasn't for the reinforcement within the concrete. I know that the purpose of the iron reinforcement is to...
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    Op amp and 3-db frequency problem

    This is the only thing that was given in the problem. There is no image or anything else. But shouldn't I first determine the 3 db frequency before sketching up the Bode plot? Also I am not quite sure how to draw the circuit. I've completed one sketch but I am not sure if it is the right thing...
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    Op amp and 3-db frequency problem

    Homework Statement An inverting amplifier with the DC gain of -9 (V/V) is built with an op amp having its DC gain of 105 and corner frequency of 30 rad/s. ▪ Determine the 3-dB frequency of the inverting amplifier. ▪ Sketch the magnitude Bode plot of the voltage transfer function of the...
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    Vibration of Rigid Body with One Spring: Understanding Torque Equations

    Alright thanks for the answer. Think I understand this now :)
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    Vibration of Rigid Body with One Spring: Understanding Torque Equations

    Homework Statement Rigid body with one spring. Homework Equations Torque equations ( M=I * "alpha") The Attempt at a Solution So I think I can solve this problem but there is only one thing I do not understand. When I am writing my torque equation I would think that the weight of the bar...
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    Engineering Basic RL circuit -- Power example

    Thank you very much. Problem solved. I just couldn't figure out what the solution was telling me but once you said they were wrong It all came together. Thanks again for the help :D
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    Engineering Basic RL circuit -- Power example

    Alright thanks for that, but isn't the impedance for inductor Zl = Jwl?
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    Engineering Basic RL circuit -- Power example

    Homework Statement A simple RL circuit in series connected to a source with V(t) = 30Cos(3t+75°)V and is delivering 14.12 W of power. I'm also given the power factor which is pf=0.857 and is lagging. Find the values of R and L Homework Equations P=Vm*Im/2 * pf for power theta =...
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    Fourier Series without complex

    Homework Statement The problem is finding the Fourier series of f(t) = e^(-t) from [0,2] where T=2 and without using complex solution. [/B]Homework Equations f(t) = a0/2 + ∑ (anCos(nωt) +bnsin(nωt) NOT using f(t) = ∑dne^(inωt)The Attempt at a Solution I tried once but got completely wrong...
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    Solving Op amp with nodal equations

    Here is another attempt, This time I got the current right but in the wrong direction, It confuses me how to determine the direction of current, It always seems like its flowing out of the node all the time at every node.
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    Solving Op amp with nodal equations

    Here is my attempted result, as you can see the current I0 is incorrect and therefor the rest of the problem is incorrect. Any tips on strategy how to solve those problems is welcome. Thank you for taking the time to help me.
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    Solving Op amp with nodal equations

    Yes of course I am trying to do this once again, I will post my results and show you.
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    Solving Op amp with nodal equations

    Homework Statement Find V0 and i0 of the circuit. Homework Equations KCL The Attempt at a Solution I tried multiple times and never got the right answer. -------------- Hello, I am having trouble solving a problem. I will link a picture of the problem with answers, but it just seems I can't...