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Homework Help: I need help really bad and fast

  1. Nov 16, 2004 #1
    finding acceleration due to gravity

    ok, i have no clue on what to do. Question: If a 13.7kg mass weighs 50.4N on the surface of ganymede. what is the acceleration due to gravity on ganymede? thats all the information that was in the question, im really confused on how to do this question because it has no other imformation............if someone would tell me if theres any formula for this question that would be great :smile:
    Last edited: Nov 16, 2004
  2. jcsd
  3. Nov 16, 2004 #2
    Do you know Newton's laws of gravitation? If you have them, or any, look at those. If you still don't understand, post the laws you know and we will go from there. But look carefully for his laws. I'm sure they're in your textbook somewhere.
  4. Nov 16, 2004 #3
    ok, the formulas i know are: Fg=mg, Fg=G (m1 m2 / R squared),
  5. Nov 16, 2004 #4
    alright take your equation Fg=mg...this is all you need to solve for the accel due to gravity on ganymede
  6. Nov 16, 2004 #5
    ok, one more problem, m=mass Fg=force of gravity g=accel due to gravity, thats what i understand them to mean, and i dont know what to do with the mass's, im very very new at this stuff
  7. Nov 16, 2004 #6
    Fg is measured in N, and then you need to manipulate the equation so g is isolated. Does that help?
  8. Nov 16, 2004 #7
    so, g=Fg/m which would be g=13.7kg/50.4N =0.27m/s^2??
  9. Nov 16, 2004 #8
    no, m=13.7 kg, Fg=50.4
  10. Nov 16, 2004 #9
    ok, so its g=50.4N/13.7kg =3.69m/s^2
  11. Nov 16, 2004 #10
    yeah, that's more reasonable than 0.27, Ganymede is a moon, not an asteroid, and yeah, that's right, it's real easy once you get the hang of it.
  12. Nov 16, 2004 #11
    thank you soooooo much,
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