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Simple question for you

  1. Sep 26, 2003 #1
    I am no science or physics major but this is my first quiz. I have this problem:
    How much force must be applied to accelerate a 10,000-kg space shuttle to counter the earth's gravitational acceleration of 9.8 meters per second square?
    I took 9.8m/s^2 * 10,000 for 98,000 newtons.
    Is that correct?
    Your help is much appreciated!
  2. jcsd
  3. Sep 26, 2003 #2


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    Staff: Mentor


    Followup: the space shuttle accelerates at roughly 3g's at liftoff. What's the force? (careful, its a bit of a trick question)
  4. Sep 26, 2003 #3

    Chi Meson

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    Homework Helper

    So far so good. Here's a conceptual helping hand: "g" is always called "acceleration due to gravity," but that's a misnomer (wrong name). An object only has an acceleration equal to "g" when it is in free fall in a vaccuum.

    Think of "g" as the gravitational field intensity, and no matter what is happening, the gravitational force on something will be "mg" . A lot of people get confused by multiplying mass times an "acceleration" when the darn thing isn't going anywhere!

    Hope this is helpful.
  5. Sep 27, 2003 #4
    It's an acceleration vector field, equivalent to accelerating at 9.8 m/s2 away from a massless earth. By the equivalence principle, the difference between being stationary in a vector field and accelerating is an illusion.
    gnickg this problem is about finding where forces balance, balanced forces are equal to each other- you solved it the right way.
  6. Sep 30, 2003 #5
    Thanks everyone for your help on my physics question. I got an "A"...!
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