1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Oribital Radius

  1. Nov 2, 2004 #1
    How do you find an orbital radius of an object around earth with its mass and Orbital Period?
  2. jcsd
  3. Nov 2, 2004 #2
    Last edited by a moderator: May 1, 2017
  4. Nov 2, 2004 #3
    Awsome, thx man. Some of these equations ive never seen before help alot lol
  5. Nov 2, 2004 #4
    Never doubt the power of Mr.Google! :tongue2:

  6. Nov 2, 2004 #5
    Kenetic/Potential Energy

    When an object eaves the surface of the ground with a certain amount of Kenetic Energy and reaches a max height what does the Potential energy equal to?

    I know the equation Ep = -Gmm/r but the question says it leaves the surface with 15 J of Kenetic energy.
  7. Nov 2, 2004 #6
    When it reaches a max height, what happens to the kinetic energy?
  8. Nov 2, 2004 #7
    It equals 0?

    Does that mean potential energy is equal to it? or negative?
  9. Nov 2, 2004 #8
    The potential energy at its max height is equal to the amount of kenetic energy the object has just after it leaves the ground
  10. Nov 2, 2004 #9
    What about in orbit? How do you solve for Ep when you have Ek if you know the acceleration due to gravity and the mass?
    Last edited: Nov 2, 2004
  11. Nov 2, 2004 #10
    In orbit with constant velocity? or is it accelerating? In space, there is no acceleration due to gravity because there is no gravity.
  12. Nov 2, 2004 #11
    Its orbiting the earth, and is at a point where gravity is equal to .233 m/s²
  13. Nov 2, 2004 #12
    I believe the equation you're looking for is:
    Gravitational Potential Energy U = mg ( yf - yi ) = mg y

    However, I'm not quite sure what you're asking
  14. Nov 2, 2004 #13
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook