Recent content by Hollumber

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    Single bead on a vertical circle.

    Yes, I don't think the bead would move, but that would be a very ideal case. Realistically, it would be shifted one way or another, and then its height determined by the angular velocity of the ring. Think of a ball at the top of a pyramid. It's in "dynamic equilibrium," where it will...
  2. H

    Finding current through resistor (Kirchhoff's Laws)

    Yes, you are definitely on the right track. Right now, it looks like you have calculated the circuit current (current through the battery). If this was a series circuit, then everything would also have the same current, but because there are some parallel components, you must calculate how much...
  3. H

    How High Can a Wheelbarrow Go Over a Step Relative to Its Wheel Radius?

    I don't think you have to worry about torque here. Just find the normal force upward as it depends on how high the step is and set it equal to the weight.
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    Calculating Kinetic and Potential Energy for Simple Pendulum - Homework Problem

    If you want the "potential energy for one whole cycle", then it means you want, essentially, a value in units of Joule-seconds. Then divide this by T to get the average. To get units of J*s from an equation giving J, an integral over time can be performed. (Hint: Should the integral go from 0...
  5. H

    Simple harmonic potentials & classical waves

    I can't think of one either.
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    Methane and CO2 atmospheric lifetime math problem

    It gives you the ratio between their effectiveness per molecule. How to change this ratio considering the effectiveness per mass instead of molecule?
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    Superposition of Waves - Standing Waves

    if cos(x-pi/2) = sin(x), what does cos(x+pi/2) equal?
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    MCAT Physics: Find Rod Length After 20% Decrease in Pendulum Period

    Mm, I wouldn't trust that. Must be some sort of misprint or mistake...unless my 6th grade teacher was wrong all this time :o
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    Help with work and vector forces

    Yes Heisen, your thinking is correct. Final KE is (integrated V + initial V)^2 *m/2, since the integrated v only accounts for speed gained due to force and doesn't consider initial v (so we add it in afterwards).
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    Transformers Turn ratio versus Impedence ratio

    After researching this so much, I finally realized where I was going wrong. (NP/NS)^2 = RP/RS is used to calculate the turn ratio of the transformer to get max power to the load resistor (RS). If this ratio doesn't hold true, then Req = RS(NP/NS)^2, where Req is the equivalent resistance that...
  11. H

    What Is the Speed of a Block Launched by a Compressed Spring?

    I think that's around the value I got as well (don't remember, but it's reasonable). Did you use (-)1.3 for delta y? If not, then your velocity is probably a little low.
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    Help with work and vector forces

    Yes, adding the velocity due to the force to initial velocity gives final velocity. Yes, this can be converted into KE. Work is equal to the difference of KE's.
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    What Is the Speed of a Block Launched by a Compressed Spring?

    Hmm, I think you can assume all the energy from the spring transfers into the object such that the spring stops decompressing at its equilibrium length. So delta s is just the distance it is compressed, and delta y is how high the block is from where it started.
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    Calculating Bullet Speed in Momentum Problem

    You should show the steps you took to arrive at your answer.
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    What Is the Speed of a Block Launched by a Compressed Spring?

    I'm not saying what you did is wrong, but to make sure you are consistent with your signs. What values did you use for delta s and delta y?
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