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Homework Help: A nuclear problem

  1. Apr 13, 2004 #1
    i need a lil help with this problem

    The earth recieves 3 x 10^22 joules of energy from the sun per day. If theis energy is expressed as mass, what is the proportional increase in the earth's mass in one year? (the ass of the earth is presently 6x10^24 kg.)
    i know to use e=mc2 but i'm not sure how and the answer is 2x10^-17
     
  2. jcsd
  3. Apr 14, 2004 #2

    HallsofIvy

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    e= mc2 so m= e/c2. (Since e is in joules, m will be in kg.) that's the "increase in mass" (per DAY!!!). Calculate the increase in one year and then find what proportion that is to the actual mass of the earth.
     
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