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!

Period of moving object

  1. Oct 5, 2008 #1
    1. The problem statement, all variables and given/known data

    The rings of a Saturn-like planet are composed of chunks of ice that orbit the planet. The inner radius of the rings is 170,000 km. The mass of this planet is 5.7x10^26 kg.
    Find the period of an orbiting chunk of ice at the inner radius.

    2. Relevant equations

    The force of gravity on the Saturn-like planet:
    g=(G)(Mass of planet)/(radius squared)
    Centripical velocity (can I do this using g from above as a?):
    a=(squared V)/r
    Then, use value of calculated v:
    V=(2)(3.14)(r)/(T) to find T


    3. The attempt at a solution

    I was able to calculate g, and used the above equations:
    g=1.3156m/ssq
    g=a (centripical)
    1.3156m=(squared v)/(1.7x10^8m)
    v=2.236x10^8m/s
    2.236x10^8m/s=(2)(3.14)(1.7x10^8m)/(T)
    T=4.77s

    The correct answer is 2x10^4s.
    Christina
     
  2. jcsd
  3. Oct 5, 2008 #2
    Can someone please help me? Please I did really try to get it on my own but I just don't understand where to go after calculating the gravity. How do I relate gravity with period?
     
  4. Oct 6, 2008 #3
    Okay, so I did a little work on my own again and am still stuck. I derived the force by setting F=G*m1*m2/r^2 and plugging in the values:
    G=6.67e-11
    m1=6.14e26
    m2=negligible
    r=7.8e7 (in meters)

    Then I set that answer equal to m*a, from F=ma, and used the m1 value from above to get a velocity of 8.167e-6m/s. Not the right answer.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Period of moving object
  1. Moving object (Replies: 3)

  2. Moving object (Replies: 5)

Loading...