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!

One more Universal Gravitation

  1. Dec 11, 2003 #1
    Ok, here's the problem:

    Neutron stars are extremely dense objects that are formed from the remnants of supernova explosions. Many rotate very rapidly. Suppose that the mass of a certain spherical neutron star is twice the mass of the Sun and its radius is 5.0 km. Determine the greatest possible angular speed it can have so that the matter at the surface of the star on its equator is just held in orbit by the gravitational force.

    I will be honest, I'm not even sure where to start... any hints on where to begin would be appreciated.
     
  2. jcsd
  3. Dec 11, 2003 #2
    What is the escape velocity at the surface of such a star?
     
  4. Dec 11, 2003 #3
    That would be

    [tex]
    v_{esc} = \sqrt_{\frac{2GM}{R}}
    [/tex]

    which I believe is about 2.2469 x 109.

    How would I relate this to the answer? I'm afraid I can't see the connection.
     
  5. Dec 12, 2003 #4
    I'll take you through it.
    How is angular speed of the star related to the linear speed of an object on the equator of the star?
     
    Last edited: Dec 12, 2003
  6. Dec 12, 2003 #5

    Doc Al

    User Avatar

    Staff: Mentor

    Consider that the rotating surface is centripetally accelerated and that gravity is the centripetal force.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: One more Universal Gravitation
  1. One more (Replies: 3)

  2. One more (Replies: 9)

  3. More on gravitation (Replies: 3)

  4. More Gravitation (Replies: 2)

Loading...