Recent content by davidj89

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    Raising and lowering operator coefficients

    never mind I got it, how do I delete my post?
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    Raising and lowering operator coefficients

    Homework Statement where a=lowering operator, ad=raising operator ad^(2)+a*ad+ad*a+a^(2) just need to find the coefficients Homework Equations ad|n>=sqrt(n+1)|n+1> a|n>=sqrt(n)|n-1> The Attempt at a Solution ad^(2)=?|n+2> ad*a=n|n> a*ad=n|n> a^(2)=?|n-2> just reviewing and can't get...
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    How Do You Calculate Observed Angular Velocity from a Reference Frame?

    maybe expand out arctan (Taylor series) and see what happens? idk how that would make it prettier (only first approximation)
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    News Is Overpopulation an Important Issue? Examining Solutions

    Honestly I think it may be colonizing other planets. I'm under the impression that in a fairly short amount of time (40-50 yrs) people will be able to choose to live for a much longer amount of time and people will still want to be popping out baby's. This means that we will either force people...
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    Could Heisenberg's Uncertainty Principle Apply Without Instruments?

    well how do you define an instrument? Your eyes sure are, which see photons bouncing off of things (such as particles) and thus effect the particles. I think the idea of "observing" something without any kind of instrument would be an interesting problem.
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    News Is Overpopulation an Important Issue? Examining Solutions

    as we are able to live longer and longer we will certainly start having very serious problems I think. Especially when we get to the point when people will be able to live for as long as they want essentially, when that happens we will have to start shooting people into space or something.
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    Photon Time: 10B Years, 0 Seconds?

    I think this is correct, the gamma factor goes to infinity, so I think that’s what the Lorentz equations tell us. That does bring up some weird ideas, like when a photon gets red shifted away by its perspective it never had time to exist so how did it have time to redshift?
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    What Are Neutrino Oscillations and Why Do They Matter in Particle Physics?

    ya do something about wave Particle Duality. You can really trip some people out with the idea of observation and how it really does change things, plus you can tac some stuff about quantum tunneling if you need more material which is also very interesting and is a product of the subject. This...
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    Temperature needed to freeze moving water

    Ya I think it would be all mechanical. You are just cooling the water to its ground state so it freezes, when you stir the water you are just bringing the water above its ground state with kinetic energy. Prob wrong but I would look at the first law of thermo dU=dQ+dW, where dU=0? so dQ=-dW...
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    Engineering Petroleum Engineer, Mechanical Engineer, or Aerospace Engineer?

    well I am a junior physics major and I have also been asking around about engineering jobs. My father is an EE and he seems to think that's a fine choice, he did say Aerospace is a hit or miss career, sometimes its booming others its a drought
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    A spring loaded gun question from my test.

    or if you feel like doing it the really clunky and obtuse way (what I did for some reason), .85=(mv^2)/2 solve for v and then its a really easy kinematics problem
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    Calculate Earth's Gravity Equation: 9.81

    the m1*a=G*m1*m2/r^2 because F=G*m1*m2/r^2 and F=ma
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    Calculate Earth's Gravity Equation: 9.81

    the way you need to think about it is m1*a=G*m1*m2/r^2, assuming you are finding the acceleration of the person or thing and not the Earth you just divide m1 (what ever the persons mass is) and all you have is G*m2/r^(2)=a, gravitational constant times mass of the Earth divided by the radius of...
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