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Homework Help: Yield of nuclear bomb

  1. Aug 14, 2011 #1
    1. The problem statement, all variables and given/known data
    The energy released by nuclear bombs is measured in kiloton (kt) or megaton (Mt) units. One kiloton is a unit of energy released by 1000 tons of trinitrotoluene (TNT). One kiloton is 4.2×1012 joules. The yield of fission bombs is typically between 10 and 500 kilotons, the yield of fusion bombs is between 1 and 50 megatons. Calculate the length of a single line of large highway trucks carrying a 74.0 kt load. The capacitity of one truck is 28.0 t, the length of one truck is 15.0 m. The spacing between the trucks is 21.0 m.

    3. The attempt at a solution
    So i divided 74000 tons by 28 tons to get 2642.857 trucks then multiplied by the length of one truck to get 39642.857 then added (21*(2642.857-2)) to get the spacing included, i subracted two because there is no spacing before the first truck and none after the last truck. but this is incorrect what did i do wrong
  2. jcsd
  3. Aug 14, 2011 #2


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    Homework Helper

    How are you thinking of the spacing? Before each truck or after it? Not both.
  4. Aug 14, 2011 #3
    well there would be spacing between every truck except the first and last truck
  5. Aug 14, 2011 #4


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    How would there be 0.857 of a truck? I would guess they want you to round up, since you can't have a partial truck.
  6. Aug 14, 2011 #5
    True I was just keeping it in to be more exact because the question is asking for how many trucks but how long the convoy is.
  7. Aug 14, 2011 #6


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    Your length of trucks is correct - though should be rounded up to2643 trucks.

    kiven you are expressing to 3 figure precision only 39.6 km of truck covers the round off anyway.
    since the "spacing" is even longer than a truck - the line of trucks will be over 90 km long.
    What was the answer you were given?
  8. Aug 14, 2011 #7
    Nevermind I got it but thanks for the help.
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