Recent content by jaidon

  1. J

    Desperate for astrophysics help

    The energy generation rate for p-p fusion has an approximate dependence on density and temperature given by: E= e (p/pc)(T/Tc)^4 i don't know how to write all the symbols so in the above: E is epsilon, e is epsilon at the centre of the star, p is the density, pc is density at the centre...
  2. J

    Spectra Troubles

    I have tried working on this the last few days, but have been unable to decide what is going on. I know there must be an easy way to do this, but for some reason i am stuck. Any help? Thanks
  3. J

    Spectra Troubles

    Consider the Lyman photons for Hydrogen-like atoms with Z greater than one. Which of these atoms have Lyman alpha photons in the 1)visible 2)UV 3)X-ray and 4)gamma-ray parts of the spectrum? Can list ranges of values of Z in the answers. My thoughts are to use 1/lambda=...
  4. J

    Absolute zero founder

    sorry don't know much about Wikipedia. is it reliable? you know how you can't be sure of some of the things you read online.
  5. J

    Absolute zero founder

    This is a pretty straight forward question. Does anyone know who exactly first determined the value of absolute zero and when it was. I am getting conflicting information about it. this is not a question i have to answer, just a little bit of information i would like to include in a physics...
  6. J

    Astrophysics - Can there be a contact binary from white dwarfs

    Question: A typical white dwarf has a mass of 1 solar mass and a radius of 10 thousand km. A typical neutron star has a mass of 1.5 solar masses and a radius of 30km. Given that there's a natural speed limit in Nature, namely the speed of light, is it possible to have a contact binary...
  7. J

    Integral help

    just wanted to let anyone who helped out with this know that my friend and i figured out, by looking at the derivative of the answer the prof gave, that there is a typo in the original question. it should not be 5x^3 (1+x^2)^1/2, but 5x (1+x^2)^1/3. it was written in such a way that i don't...
  8. J

    Integral help

    sorry Gamma, missed your post about the answer being wrong. glad to here that i am not way off base on this. thanks all for your input
  9. J

    Integral help

    does anyone agree with me that maybe the answer given by my friend's sheet is incorrect?
  10. J

    Integral help

    sorry, but i'm not sure how your answer is equivalent to the answer she was given ie)15/8(1+x^2)^4/3 +C. also, i guess i wasn't clear in my last post. they haven't done trig subs, by parts, partial fractions, etc, nothing like that yet. all they have done is u subs. this isn't even my...
  11. J

    Integral help

    wow. that is unlike either answer i posted. i guess i should have stated that the only special way they have learned to solve integrals is with a u sub. did you see what exactly i did wrong in the way i tried to solve it? sometimes one needs an extra pair of eyes to find the error.
  12. J

    Integral help

    this should be easy, but i'm struggling. i'm trying to help a friend solve: integral(5x^3(1+x^2)^1/2), sorry i don't know how to do the integral sign. i did a u sub with u=1+x^2, du=2xdx and u-1=x^2 so: (5/2)integral((u-1)(u)^1/2) i get (1+x^2)^5/2-10/6(1+x^2)^3/2 +C the...
  13. J

    Theory question

    this is probably a stupid question, but what exactly qualifies as macroscopic ie)what is the actual range? also, i get the question now. it was much simpler than what i was trying to make it out to be. thanks for the imput. you physics guys rock.
  14. J

    Theory question

    so the size of macroscopic objects is much larger than what the uncertainty in their positions. i'm not sure what this means in regards to quantum mechanics. i find quantum physics so confusing and i highly respect anyone who understands and enjoys it.
  15. J

    Theory question

    i have a question where it asks me to find the uncertainty in a ball's postion (m=50g). i have that part all figured out, but then it asks me what the answer indicates about the relevance of quantum mechanics to macroscopic objects. (the answer was approx. 10^-32m, a very small uncertainty)...
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