Escape velocity question - constant is wrong....

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Homework Help Overview

The discussion revolves around a question related to escape velocity and orbital mechanics, specifically addressing a multiple choice problem that initially seemed to require escape velocity for a solution.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants explore the nature of the question, with some initially assuming it pertains to escape velocity, while others clarify that it does not require escape velocity for orbiting at a fixed radius. Arithmetic errors are also noted in the calculations presented.

Discussion Status

There is an ongoing clarification regarding the nature of the question, with some participants recognizing the misinterpretation of the problem. Acknowledgment of arithmetic errors has been made, and the discussion is evolving as participants adjust their understanding.

Contextual Notes

Participants are navigating assumptions about the requirements for orbital motion versus escape velocity, indicating a potential misunderstanding of the problem's context.

maxelcat
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Homework Statement
A planet of mass M and radius R rotates so quickly that material at its equator only just remains on its surface.
What is the period of rotation of the planet?

This is a multiple choice question. I must be doing something wrong.9
Relevant Equations
V=-GMm/R=0.5mv^2
This is a multiple choice question. I assumed that this is an escape velocity question. I have been going round and round...
Here's what I have done:
1663239000057.png
 
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It is not an escape velocity question. You do not require escape velocity to just orbit at a fixed radius.
 
Also you made an arithmetic error. Your answer should be wrong by √2
 
yes - found that.
 
and yes, it is not an escape velocity question. D'oh - I see that now.

Thanks
 
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