Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Strange question

  1. Jun 18, 2003 #1
    So I came across a question in a quiz book the other day and I still haven't been able to answer it, so I figured I would ask some experts... Here goes...


    As a NASA senior physicist, would you agree with the calculation made by a junior physicist regarding the speed of an artificial satellite, v = 3 x 10^4 m/s, assuming that it is travelling at an altitude h = 230 km above the earth's surface where g = 9.0 m/s^2. The radius of the earth is 6370 km.
     
  2. jcsd
  3. Jun 18, 2003 #2

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I would disagree.

    For all circular motion, a = v2/r, where a is the centripetal acceleration, v is the linear velocity, and r is the radius of the circle.

    Plug the numbers in, and you'll see there's a contradiction.

    The satellite should be moving at roughly 7,000 m/s, not 30,000 m/s.

    For more info on circular motion: http://hyperphysics.phy-astr.gsu.edu/hbase/circ.html#circ

    - Warren
     
  4. Jun 18, 2003 #3

    enigma

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Yep,

    If the sat is going at that speed and altitude, it won't be at that altitude for long.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Strange question
  1. Strange attractor (Replies: 3)

  2. Strange Magnets (Replies: 2)

  3. Strange current (Replies: 7)

Loading...