Recent content by flatmaster

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    Does All Gravitational Energy in Water Convert to Heat?

    I am writing an intro physics problem about a flowing stream. I am going to assume that all of the gravitational potential energy eventually becomes thermal energy of the water. I haven't worked it yet, but I'm pretty sure the flow rate and g will both cancel out and give me a constant change...
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    Free falling object violating conservation of energy?

    I think you may be thinking that potential energy has an absolute scale and that there is some place where height=0. The exact value for the height isn't important. It is the change in height that is important. Immagine you were to perform a similar experiment in a very tall building with...
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    Permanent marker to decorate a coffe mug

    I am looking to decorate some coffee mugs with a permanent marker. People have tried this before and attempted many different techniques for keeping the dried ink on the mug. http://www.craftaholicsanonymous.net/21-tips-for-diy-sharpie-marker-mugs The most common technique involves...
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    Why is Sin the convention for the harmonic oscillator?

    In the course of solving the simple harmonic oscillator, one reaches a fork in the road. x(t) = A1Sin(wt) + A2Cos(wt) At this point, you exploit a trig identity and arrive at one of two solutions x(t) = B1Sin(wt+phi1) or x(t) = B2Cos(wt+phi2) Both of these are correct solutions...
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    How Is the Mass of the Top 3.2 Meters of the Ocean Calculated?

    So the location of the bottom changes that much over 3.2 meters of depth?
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    Terminal Voltages of a flashlight cell?

    The question is worded a bit ambiguously, but I think I know what they mean. In your attempt at the solution, you assumed that BOTH pairs of terminals were connected. I think they are asking what would happen if ONE pair of terminals were touching.
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    Understanding Units: Multiply vs Divide

    Have you had calculus? Velocity has units of m/s. Velocity is the DERIVATIVE of position with respect to time. Weber has units of V*s. Magnetic flux (Weber) is the INTEGRAL of voltage with respect to time.
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    Finding the time when two stones cross paths

    Missed my third point… "-9.8t2 = 6.69 getting negative time…?" Nope, you wouldn't get negative time. It's even weirder; You would have imaginary time!
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    Finding the time when two stones cross paths

    Good start. Three things… 1. Keep your numbers as variables. It's a lot easier to keep writing "g" than to keep writing "-9.8 m/s2[up]". 2. You said. "distance traveled by both rock A and rock B combined is 6.69 DA + DB = 6.69" THis is close, but not quite correct. We don't know that...
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    Electronics Lab Prep: Filters & Transfer Functions

    You're getting there. You need to think about what the graph function would look like around the resonance in addition to the value of H(w) at the resonance. At the resonance, you would expect the value of H(w) to be at a local maximum. How can you determine if your function is at a maximum...
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    555 timer question & Bounceless Garage door opener.

    It's an older model, so it doesn't have the light beam. Manufacture is Allister. Radio receiver is delta 3. Not sure what the force required for bounce back is. I think I'll put some aluminum cans and see if it crushed them. The delay I built is only on the radio receiver. Hard wired...
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    Equilbrium temp of ice and steam mixture

    Personally, I would prefer to work through the algebra rather than doing SteamKing's bookkeeping technique. You missed one major simplification that you could have done very early in your algebra. You noted that you can factor out an m from everything. However, you kept m around for a...
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    Electronics Lab Prep: Filters & Transfer Functions

    If there is a resonance, what should happen to the value of H(w) when w-->w0 from either direction on the w axis?
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    555 timer question & Bounceless Garage door opener.

    Door will bounce back when hitting an obstacle. Otherwise, you need to wait the 3 seconds for the 555 to reset. This is enough time for door to go through about 1/3 of its total travel.
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    555 timer question & Bounceless Garage door opener.

    Ok. Regulating voltage to 12 VDC. Installed diode in parallel with relay coil side to handle collapsing inductor field. The 555 output is rated at 200 mA and I measured the relay drawing 20 mA at 12 VDC. Do I really need to make the 555 drive a transistor instead of driving the relay directly...
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