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Homework Help: Rocket propulsion

  1. Oct 18, 2013 #1
    1. The problem statement, all variables and given/known data
    A rocket in outer space has a payload of 4050.0 kg and 1.753·105 kg of fuel. The rocket can expel propellant at a speed of 4.300 km/s. Assume that the rocket starts from rest, accelerates to its final velocity, and then begins its trip. How long will it take the rocket to travel a distance of 3.82 ·105 km

    2. Relevant equations
    [itex] V [sub c] ln(m [sub i]/ m [sub f])

    3. The attempt at a solution
  2. jcsd
  3. Oct 18, 2013 #2
    I found the final velocity, but when i tried to use the formula for distance, I found that I didn't have r sub p or T max and have no clue how to find them.
  4. Oct 18, 2013 #3


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    You need to post all the equations you are referring to and define any symbols in them which might not be completely obvious to readers. (Even the "relevant equation" you posted is not an equation.)
  5. Oct 18, 2013 #4

    D H

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    Staff Emeritus
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    Psyguy22, please look at what you posted. You did not mean 1.753·105 kg of fuel, you meant 1.753·105 kg of fuel. There's a huge difference between 184.065 kilograms and 17,530 kilograms.
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