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  1. #1
    Crushing souls Hickeydog's Avatar
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    Need chemistry/phiscis help

    These questions are starting to piss me off....anyways

    Cobalt-60 is a radioactive isotope used to treat cancers of the brain and other tissues. A gamma ray emitted by an atom of this isotope has an energy of 1.33 MeV (million electron volts; 1 eV = 1.602e-19 J). What is the frequency (in Hz) and wavelength (in m) of this gamma ray?

    I used the equation E=HC/lambda (E is energy, H is Plank's constant, 6.63e-34, C is the speed of light, 3.0e8, and lambda is the wavelength.) I solved for lambda and got HC/E=lambda. Plug and chug and I get 1.2e-6m. Only problem is, that's not the correct answer. So what am I doing wrong?

    Edit: Okay. First problem was that I didn't convert 1.33 MeV to J. So I re-did the calculations with 2.13066e-19J and came out with 9.3e-7m and that's still wrong. So my question still stands.
    Last edited by Hickeydog; 10-28-08 at 06:51 PM.
    Quote Originally Posted by Wordbiker View Post

    What's frightening is how coherent Hickey was in posting that.

  2. #2
    Senior Member Lamplight's Avatar
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    First I think you may need some spelling help.







    Sorry! I couldn't help myself!

  3. #3
    Crushing souls Hickeydog's Avatar
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    what was spelled wrong?
    Quote Originally Posted by Wordbiker View Post

    What's frightening is how coherent Hickey was in posting that.

  4. #4
    Blasted Weeds Tude's Avatar
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    Quote Originally Posted by Lamplight View Post
    First I think you may need some spelling help.







    Sorry! I couldn't help myself!
    Me too

    (and I can't help with the phiscis question either)


  5. #5
    Blasted Weeds Tude's Avatar
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    Quote Originally Posted by Hickeydog View Post
    what was spelled wrong?
    physics.

    Well, unless it's Fizz-ics or Phizycs or ...

  6. #6
    Crushing souls Hickeydog's Avatar
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    thanks. figh1fight1figh1fight1
    Quote Originally Posted by Wordbiker View Post

    What's frightening is how coherent Hickey was in posting that.

  7. #7
    Crushing souls Hickeydog's Avatar
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    never mind. I figured the ****ing thing out.
    Quote Originally Posted by Wordbiker View Post

    What's frightening is how coherent Hickey was in posting that.

  8. #8
    Blasted Weeds Tude's Avatar
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    LOL (and glad ya figured it out)

  9. #9
    Crushing souls Hickeydog's Avatar
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    and I am about ready to KILL someone



    ggggggrrrrrrrrrrrrrrrrrrrrrr

    *starts looking for murder weapons*
    Quote Originally Posted by Wordbiker View Post

    What's frightening is how coherent Hickey was in posting that.

  10. #10
    Blasted Weeds Tude's Avatar
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    slips out the side door ... - it wasn't me ...

  11. #11
    long time visiter Alfster's Avatar
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    After seeing the title, with likely the worst, incorrect spelling I've seen yet for 'physics', I had to check to see if this was a joke thread. It wasn't

  12. #12
    long time visiter Alfster's Avatar
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    Wait, did you say you were about to kill someone? Please disregard my last post.

  13. #13
    T-Shirt Guy ehidle's Avatar
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    Quote Originally Posted by Hickeydog View Post
    These questions are starting to piss me off....anyways

    Cobalt-60 is a radioactive isotope used to treat cancers of the brain and other tissues. A gamma ray emitted by an atom of this isotope has an energy of 1.33 MeV (million electron volts; 1 eV = 1.602e-19 J). What is the frequency (in Hz) and wavelength (in m) of this gamma ray?

    I used the equation E=HC/lambda (E is energy, H is Plank's constant, 6.63e-34, C is the speed of light, 3.0e8, and lambda is the wavelength.) I solved for lambda and got HC/E=lambda. Plug and chug and I get 1.2e-6m. Only problem is, that's not the correct answer. So what am I doing wrong?

    Edit: Okay. First problem was that I didn't convert 1.33 MeV to J. So I re-did the calculations with 2.13066e-19J and came out with 9.3e-7m and that's still wrong. So my question still stands.
    You're missing a factor of 1 million.

    if 1eV = 1.602E-19, then 1.33 MILLION eV = 1.602E-19 * 1.33E+06 = 2.13066E-13, not -19.
    Yellow + Blue Jerseys!

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  14. #14
    You Know!? For Kids! jsharr's Avatar
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    I think I may submit this thread to fail blog.
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    Quote Originally Posted by colorider View Post
    Phobias are for irrational fears. Fear of junk ripping badgers is perfectly rational. Those things are nasty.

  15. #15
    riding once again jschen's Avatar
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    Carrying units along in your calculations would have immediately revealed the problems. One should always carry units.
    If you notice this notice then you will notice that this notice is not worth noticing.

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