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Homework Help: Gravity away from earth

  1. Apr 14, 2008 #1
    If a rocket launches from the earth, how can i calculate the change in acceleration due to gravity as it gets farther and farther away? Thanks!
  2. jcsd
  3. Apr 14, 2008 #2


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    Science Advisor

    Well, if you're familiar with the universal law of gravitation.. F=(G*m1*m2)/(R^2). And F=ma so...
  4. Apr 14, 2008 #3

    D H

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    Staff Emeritus
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    This looks like a homework problem. Had you submitted this in our homework section, you would have been prompted to tell us the relevant equations and describe the work you have done to solve the problem. So, lacking those automated prompts, I am prompting you now. What are the relevant equations and what have you done to solve the problem?
  5. Apr 14, 2008 #4
    it actually is not a homework problem...
    In response to Nabeshin-
    Ok I thought i could just do this but someone told me otherwise...
  6. Jun 3, 2008 #5


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    Staff: Mentor

    Thread moved to Homework Help anyway. Please take care to post anything homework-like in the Homework Help forums. The PF Rules (see link at top of the page) are pretty clear about that.

    And on your question -- what can you tell us about the sum of the forces on the rocket, and how that sum is related to the rocket's acceleration? Also, what can you tell us about the rocket's mass over time....?
  7. Jun 3, 2008 #6
    Depends, either let it decline radially through newton's law, or you could use a rotating rocket around the earth, and try and calculate its minimum height with corresponding speed to rotate around earth, using gravitational acceleration as a centripetal force.
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