1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    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!

How can this be wrong? (Simple circular motion)

  1. Oct 4, 2006 #1
    "An Earth satellite moves in a circular orbit 730 km above the Earth's surface. The period of the motion is 99.2 min. What is the magnitude of the centripetal acceleration of the satellite?"

    OK so to solve this I used the formula centripetal acceleration = v^2/r

    To calculate velocity (v) I did the following:

    v = distance travelled (d) / time taken (t)
    d = 2piR = 2 x pi x 730,000 = 4586725.274m
    t = 99.2 x 60 = 5952s
    v = d/t = 4586725.274/5952 = 770.619ms^-1

    Then we already have r which is 730,000m so v^2/r is:

    770.619^2/730,000 = 0.813ms^-2

    But this is answer is wrong...HOW?!
     
  2. jcsd
  3. Oct 4, 2006 #2

    George Jones

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    From is where is the radius of the orbit measured?
     
  4. Oct 4, 2006 #3
    Ah! So I need to add the radius of planet earth to the overall radius?
     
  5. Oct 4, 2006 #4

    George Jones

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    You aren't given an overall radius, you are given the height above the Earth's surface. You need to find the radius of the circle that is the orbit.

    It looks like you're basically on the right track.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: How can this be wrong? (Simple circular motion)
Loading...