Recent content by sphoenixee

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    Probability semiconductor problem

    I'm not an expert, but I thought your problem was interesting and had some free time, so I tried it. here's what I got. #1----------------------- Each location is either contaminated or not and there are 6, so 2^6=64 #2------------------------ No contamination particles=0.6*.8*.85*.9*.95*.9 This...
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    Volume of a Solid by Revolution

    Your answer looks right. I'd say the super trustworthy internet is wrong ;). (Disclaimer: I'm getting back into calc after a year of none, but still I'm quite sure you're correct).
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    What is the Most Rational and Logical Form of Government According to Science?

    The best form of government...mmmmmm. I wonder if there is an answer to that. If there is, then why are not all governments the same form? Thus, I don't think there is. Furthermore, as stated by others, it's important to consider for whom and by whom the government is. For example, a group of 20...
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    Toy Propeller Efficiency: Range of Efficiencies

    Question: what is the range for propeller efficiency for plastic toy propellers?
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    Problem Solving Skill vs. Knowledge

    I chose choice 2. New knowledge is great, but unless you know how to apply it and practice with it, you're going to forget it. My favorite encounters with math are through high school math contests, and in this arena at least, practice>>>>knowledge. I'd say that 2 years ago I knew most of the...
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    Do you really need a calculator?

    Calculators are super useful for arithmetic jobs, solving higher order polynomials, matrices (anyone up for inverting 4x4 XD), statistics definitely, calculus somewhat and of course, graphing. In terms of 83+, it is mildly useful for calc. Sort of a bummer there's no indefinite integral (no...
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    Need help with Trig/angle question

    To convert from rectangular (x,y) to polar (r,theta): r=Sqrt[x^2+y^2] theta=arctan(y/x), after which you must consider the given quadrant See wikipedia: http://en.wikipedia.org/wiki/Polar_coordinate_system#Converting_between_polar_and_Cartesian_coordinates If you get an irrational answer...
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    Can People Fly? Investigating Human Flight Possibilities

    I'm a youngster now? You got an elixir? (Now, that'd make you rich...) I was being a bit harsh, yes, and my humblest apologies for that. I do appreciate and highly value your insightful comments. Nevertheless, I still don't appreciate ridiculing of my project or discussion of completely...
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    Can People Fly? Investigating Human Flight Possibilities

    I realize that many of you think this is a joke, but please realize that my project does involve far more than ornithopter flight. It's just that I had a question specifically about this part and wanted some input. So, if you don't have anything related or helpful to say, then please don't waste...
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    Crookes's Radiometer: Thermal Transpiration Explained

    The radiometer does rotate reverse if you put it in a refrigerator. This is because the black sides cool off faster than the silver sides. I don't know what you mean by the latest theory of thermal transpiration, but thermal transpiration has been used to explain Crookes Radiometer ever since...
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    Can People Fly? Investigating Human Flight Possibilities

    Many many thanks to all for the posts. I'll be sure to share my experiences when I'm done. sphoenixee
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    Weight of 12 fl oz Beer Bottle | Physics Project Help

    Random question: How much does a regular beer bottle (12 fl oz) weigh? I'm doing a physics project involving the weight of beer bottles, and I don't have a scale, balance, etc. :rolleyes:
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    Rotational Equilibrium and Dynamics Problem

    Why does the mass of the pulley not matter? The pulley is also being accelerated at the same rate as the rest of the system, so if one wants to apply F=ma, then one needs the mass of the pulley in addition to the mass of the two masses. My bad about the acceleration = 4g. I meant that the...
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    Rotational Equilibrium and Dynamics Problem

    andrevh, how does that do anything? So what, I use m3 and m4 and T3 and T4 instead of m1 and m2 and T1 and T2. I could've told you that when I was 7 for crying out loud. I really do appreciate any efforts at helping, but changing the names of variables is quite useless...or am I missing...
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    Rotational Equilibrium and Dynamics Problem

    Homework Statement A hanging 4 kg mass is connected by a weightless cord on a pulley to a 3 kg mass which rests on a smooth surface. The pulley has frictionless axle and I=.5kgm^2 and r=.3m. The cord does not slip on the pulley. Find the acceleration of the two masses and the tensions of the...
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