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    Dynamics question. inclined plane

    Hi Raye, Maybe we'll have more luck if you could please post the exact text of the original question. But at a minimum, you're definitely going to need to consider the friction on the ramp; keep in mind that work = force times distance, and the whole time you are pushing against those friction...
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    A child slides down a ball of ice.

    Hi zaddyzad, I'm going to assume that the child was sitting on the top of the circle, initially at rest, though initial conditions aren't really clear from your attachment. Try these steps: 1. After sliding down to some angle theta, how far has the child fallen? Therefore, how much kinetic...
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    A uniform solid cylindrical log begins rolling without slipping down a ramp that rise

    Hi Mdhiggenz, The problem is in your first calculation, where you come up with 7.41m/s. Your manipulation of the algebra looks correct to me (double check!), but at the very last step you seem to have used h=4.20m. The problem says that the log moved 4.20m along the ramp, which means it would...
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    Work and frequency caused by mutual potential energy

    Hi phys17, Never in all my years have I encountered a 1/r^10 term in a potential. Am I reading this correctly - you mean 'one over r to the power of ten'? I guess there's nothing actually wrong with that - you can write down any wild potential you want - but I don't think anyone here is going...
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    Bernoullis principle and lift on a wing of plane

    Hi bfusco, I think we could help a bit more if you told us what exactly you meant by 'Bernoulli's principle' here; there are a lot of different kind of similar things that can be labeled 'Bernoulli's principle', and I don't want to steer you wrong. Qualitatively, you already stated & explained...
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    Humphrey the Singing Whale and his mate Matilda.

    Hi ScienceGeek24, I can confirm that 5.11m/s is the correct answer, and that you're starting out from the right Doppler effect equation - you're on the right track! Just be careful of your signs (the whales are moving in opposite directions, but I think you got that from your +- / -+ notation...
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    Uniform Circular:Motion What happens to the accuracy as the frequency as it increases

    Hi n3w ton, I don't blame you for struggling with this problem; the wording of it is very awkward. I will take my best stab at it, but I make no promises that I have correctly read your instructor's mind: The key point is (probably?) in the experimental method where you're told to measure the...
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    Potential energy

    Hi Jalo, I find it a bit unclear what 'balance points' refer to here - my only guess is potential minima, which will have to be in all three dimensions at once (not just x and y like you guessed). Consider the gradient of the potential function and see if that leads you anywhere, Hope this...
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    Why a two-slit experiment with electrons is evidence electrons are waves?

    Hi nukeman, One of the key points of a two-slit experiment is that you can fire a single electron at a time at the slits, and if you don't detect which slit it goes through, you will still observe an interference pattern built up over time. This doesn't make sense if the electron is a...
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    Energy conservation problem

    Hi Jalo, First let's double-check part (a). You start off really well, by noticing that the gravitational potential energy of the particle initially is PE = mg*(2R+b). Since the particle starts at rest, this is its total energy for the whole problem, due to conservation of energy and since...
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    Understanding Potential Energy

    Hi 4570562, It looks to me like your calculus and physics textbooks are talking about slightly different things. Your calculus book is giving you a discussion of formal vector fields, whereas from the notation, I take it that your physics text is just considering some simple scalar work and...
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