Recent content by Rumpelstiltzkin

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    What is the mass of the raindrop?

    1) First you need to understand the question well. Terminal velocity means means the sum of forces is zero. They've given you one force, which is air resistance. What's the other force? Be careful with the directions, forces are vectors. 2) Three things you need to know about friction: i)...
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    Solving a Triangle: Verifying, Calculating Area & Perimeter, and More!

    1) Let PQ and QR be two vectors. If two vectors are perpendicular, the cross product of those two vectors will equal to 1. 2) Find the length of PQ and QR. I think the area should be pretty easy to find. 3) Again, self-explanatory. Use the pythagorean theorem to find the length of the remaining...
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    Power in voltage dependent source

    No you're not getting it... Equation 2 is still wrong. You're confusing current and voltage. 7Io is NOT the current through the dependent source. Look at its circuit symbol. It's a CURRENT-DEPENDENT VOLTAGE SOURCE. That means it's actually a VOLTAGE SOURCE, which depends on CURRENT. Okay...
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    Power in voltage dependent source

    132V + 7Io is the voltage of the node to the left of the 7-ohm resistor (since you didn't label it, let's call this node B). The voltage of the node to the left of the 2-ohm resistor is 7Io (let's call this node A). The 132V voltage source increases the electric potential (that is, "voltage")...
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    Power in voltage dependent source

    The voltage on that node is not known. It's not 132V. It's 7Io; the voltage depends on the current Io, which is through the 10-ohm resistor. So you have to obtain an equation for Io in terms of V2.
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    Filter Network - (answer does not match books)

    You sure it's not: \bar G_v(j \omega ) = \frac{j \omega C (R_1+R_2)+1}{j \omega C R_1 +1} Anyway, I think your nodal equation is incorrect. KCL states that the sum of all currents flowing out of the node equals to zero. Vi/a and (Vi-Vo)/b are both currents flowing out of the node. So it's...
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    Power in voltage dependent source

    The current flowing through the 2-ohm resistor is not (v2-132)/2.
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    Tension of strings at different angles:

    They're not correct. Draw a free body diagram and check your directions. Are T2cos25 and T1cos15 the vertical components or the horizontal components of the string tensions?
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    Understanding the Difference Between Parallel and Series Circuits

    For question 1, it states that the current through the ammeter is 0.6 A when the switch is open. The trick is this: Does current flow through the 3rd resistor when the switch is open? What happens when you close the switch? Does current flow through the 3rd resistor now? Does it affect the...
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    How Can I Graph THis trigonometric Function?

    Look in the first link you posted. It tells you what happens when you multiply by 2. BTW, when you add 2, it's not the y-axis that moves. The y-axis does not move. Ever.
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    What is Torque? How Is It Measured?

    Fast? Don't you mean distance? Actually there are lots of real-world examples you can think about to get the idea about torque. For instance, consider a door. Notice that the doorknob is always as far as possible from the hinge (which is the axis of rotation). What happens if the doorknob is...
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    Solving a Statics Problem: Finding Reactions Forces

    Here's a statics problem that I'm unsure about. The system is in static equilibrium, and I'm supposed to find the reaction forces. {convention: right and up are taken as positive for x and y respectively, and counter-clockwise is positive for moment} \sum F_{y} = 0 B_{y} = -1000N \sum F_{x} =...
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