1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Physics Centripetal Force problem?

  1. Feb 11, 2016 #1
    1. At what rate a space station 200m in diameter would have to rotate to create gravity equal to 0.7 that at the surface of earth. How fast does it spin, and how long would it take to make a complete rotation?

    2. a2 = v2 / 100m
    T = 2pi(r) / v

    so far: 6.867m/s2 = v2 / 100m = 26.2 m/s

    T = 2pi(100) / 26.2m/s = 24 sec

    did I do it right?
  2. jcsd
  3. Feb 11, 2016 #2


    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    Welcome to PF!

    Your work looks good. The phrase "how fast does it spin" might refer to angular speed rather than linear speed at the outer rim.
  4. Feb 11, 2016 #3
    The problem is word for word so I assume they're asking for angular speed.
    Am I correct, though?
  5. Feb 11, 2016 #4


    User Avatar
    Homework Helper
    Gold Member
    2017 Award

    If they're asking for angular speed, then you need to calculate the angular speed. I believe your answers for the linear speed and period of rotation are correct.
  6. Feb 11, 2016 #5
    w = 2pi / T
    w = 2pi / 24 = .2618 rad/sec
    is that correct?
  7. Feb 11, 2016 #6
    Yes. It's also v/r = 26.2/100=0.262 rad/sec
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Threads - Physics Centripetal Force Date
Centripetal Force and circular motion Dec 8, 2017
Magnitude of force of a disk on a circular track Apr 18, 2017
Centripetal Force Jul 1, 2016
Centripetal Force hydrogen atom Nov 17, 2015