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Having trouble with problem

  1. Sep 6, 2004 #1
    I have a physics problem that I am stuck on: Approximately 4 x 10^9 kg of matter is converted into energy each second in the sun. Find the power output of the sun. I know the answer is 3.6 x 10^26 W I just can't figure out how to get the correct equation and numbers. Any help would be appreciated. Thanks
  2. jcsd
  3. Sep 6, 2004 #2


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    The relevant equation is
    [tex]E = mc^2[/tex]
  4. Sep 6, 2004 #3
    Use [ tex ] E = mc^2 [ /tex] to convert the mass to energy, then power is just energy per unit time.
  5. Sep 6, 2004 #4
    Thanks! I knew it was something easy!
  6. Sep 6, 2004 #5
    ...why not e=mc^2?
  7. Sep 6, 2004 #6
    LOL sorry must've left the window on too long... haha
  8. Sep 6, 2004 #7
    [tex]P=\frac{\Delta e}{\Delta t}=\frac{\Delta mc^2}{\Delta t}[/tex]
    Given [tex] \frac{\Delta m}{\Delta t}= 4*10^9 kg/s[/tex]
    [tex]c=3.00*10^8 m/s[/tex]
  9. Sep 7, 2004 #8


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    This reminds me of a lecture my (lively) optics professor gave.
    He asked us to just imagine four billion kilograms of matter being
    converted every second. :surprised
    "Suppose you would throw 700 g brick up into outer space every second. (he freely demonstrates what it would be like).
    Now imagine all the people in the world doing that." It's amazing :bugeye:
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