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

Distance of a satellite from earth

  1. Feb 23, 2009 #1
    Distance of a satellite from earth....

    1. The problem statement, all variables and given/known data
    A microwave signal is received from a satellite in orbit round earth, 68 ms after it was transmitted from the satellite. Calculate the height of the satellite?

    This sounds like such a simple questions and i reckon it is except i always seem to get stumped.... I first tried to figure out the angular velocity of the satellite but you don't know enough information to calculate that, then i kept going round in circles??? What am i missing??
    A poke in the right direction would be very appreciated....
  2. jcsd
  3. Feb 23, 2009 #2

    Gib Z

    User Avatar
    Homework Helper

    Re: Distance of a satellite from earth....

    The problem is much simpler than you are thinking!

    You know the Speed of the signal (c), and you know the time it took to get down to earth. What equation most simply relates speed and time with the variable you are looking for?
  4. Feb 23, 2009 #3
    Re: Distance of a satellite from earth....

    According to my calculations it's indeterminate, but somewhere between 12.7 and 9.3 thousand miles away, to be determined by position in the sky.
  5. Feb 24, 2009 #4
    Re: Distance of a satellite from earth....

    h=ct and c=3x10^8 so h=2.04x10^7m Thanks Gib Z
    wow that was incredibly easy!!!! jezz i really need think a bit more
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook