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Homework Help: Calculate rpm with circular motion

  1. Oct 22, 2012 #1
    1. The problem statement, all variables and given/known data
    Imagine that NASA plans to builds a large donut-shaped space station. The station will rotate in outer space in order to simulate gravity. If the station has a radius of 200m, what must be its rotation speed in revolutions per minute, to produce an artificial gravity of 0.8 g?

    2. Relevant equations
    rev/min = 60v/2pi*r

    3. The attempt at a solution
    Okay, so I have somewhere in my notes that if ac = g then T = 0. So I replaced ac with 0.8. So my equation went 0.8 = v^2/(200m).

    So I got my v = 12.65 m/s.

    Then I plugged my v into rev/min at 60(v)/2pi*r and I got my answer to be 0.604 rev/min.

    I was just wondering if I did this right?
  2. jcsd
  3. Oct 22, 2012 #2

    Simon Bridge

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  4. Oct 23, 2012 #3
    How do I solve for rpm? I think my v is correct.
  5. Oct 25, 2012 #4

    Simon Bridge

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    Well, since you are sure you have the correct v...
    You can either convert your v into angular velocity or work out the circumference of your circle and how many times you'd travel that distance at speed v in one minute.

    However, if you don't answer questions I cannot help you.
    i.e. is 0.8g, the acceleration you are asked to get, the same as 0.8m/s2 - which is the acceleration you used to get v?
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