Rotational motion and law of gravity

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Homework Help Overview

The discussion revolves around a problem involving rotational motion and gravitational forces, specifically focusing on neutron stars and their angular speed. The original poster presents a scenario where a neutron star's mass and radius are given, and the task is to determine the maximum angular speed that allows surface matter to remain in orbit due to gravitational force.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the relationship between gravitational force and centripetal force, with attempts to equate them. Questions arise regarding the correct formulation of the equations and the inclusion of mass terms.

Discussion Status

There is an ongoing exploration of the problem, with participants providing guidance on the necessary equations and questioning the original poster's steps. Some participants suggest reviewing the definitions and components of the forces involved, while others express uncertainty about the next steps.

Contextual Notes

Participants note the need for clarity on the variables involved and whether all necessary information is available to proceed with the solution. There is an emphasis on ensuring that all terms are accounted for in the equations being used.

wowdusk
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Homework Statement


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 10.0 km. determine the greatest possible angular speed the neutron star can have so that the matter at the its surface on the equator to be just held in orbit by the gravitational force.


Homework Equations





The Attempt at a Solution


i no that the gravtiational force must equal the Force
so GM/r^2=mV^2/ R, but where do i go fom here I am lost!
 
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...still lost... idk what to do...
 
i no that the gravtiational force must equal the Force

So the gravitational force must equal the net force? Which is the centripetal force.
Fg=Fc
So I think you got this far already, but it looks as though you made a small mistake on this next step when you came up with this equation:
GM/r^2=mV^2/ R
You may have forgotten to either include a mass term or cross one out.. look at the equations for Fg and Fc again.
 
ok you so i get GMm/r^2=mV^2/R, but still don't know what to do
 
What is the question asking us to solve for?

Do you have everything you need to solve for it? I often make a list of everything that's been given, even before starting.

R=?
V=?
M=?
m=?
G=?
 

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