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Homework Help: Esacpe speed - energy required

  1. Jan 19, 2012 #1
    1. The problem statement, all variables and given/known data

    A space probe is launched from the equator in the direction of the north pole of the Earth. During launch the energy given to the probe of mass m is


    Deduce that the Space probe will not be able to travel into deep space

    2. Relevant equations

    Minimum KE needed = - GMm/R

    3. The attempt at a solution

    I said that if minimum KE was as above then having three times that would mean that it would escape but the answer is that it won't so I'm puzzled? How do I deduce that it won't escape if it has 3 times the energy E=(3GMm/R)
    Last edited: Jan 19, 2012
  2. jcsd
  3. Jan 19, 2012 #2
    Should it have a negative sign in front of it, I remember something bout infinity? Please help!

  4. Jan 19, 2012 #3


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    Homework Helper

    hmm. You're right, that the probe should be able to completely escape from the Earth's gravitational field... Maybe you are also supposed to take into account the gravitational field from the sun?...
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