Escape velocity question - constant is wrong....

Click For Summary
The discussion clarifies that the question posed is not about escape velocity, as orbiting at a fixed radius does not require it. An arithmetic error was identified, leading to a correction that the answer should be adjusted by a factor of √2. Participants acknowledge the misunderstanding regarding the nature of the question. The conclusion emphasizes the importance of correctly identifying the type of physics problem being addressed. Understanding the distinction between escape velocity and orbital mechanics is crucial for accurate problem-solving.
maxelcat
Messages
33
Reaction score
4
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
 
Physics news on Phys.org
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
 

Similar threads

Variation of escape velocity with equal surface gravity
  • · Replies 7 ·
Replies
7
Views
1K
Where in orbit should a rocket fire to escape with minimum ΔV
  • · Replies 17 ·
Replies
17
Views
3K
Velocity required to escape the solar system
  • · Replies 15 ·
Replies
15
Views
1K
Escape velocity of solar system
  • · Replies 11 ·
Replies
11
Views
3K
Calculating Escape Velocity for Earth: Where Am I Going Wrong?
  • · Replies 2 ·
Replies
2
Views
2K
A mistake in the derivation of escape velocity
  • · Replies 5 ·
Replies
5
Views
2K
Escape velocity of an iron asteroid
  • · Replies 5 ·
Replies
5
Views
2K
Gas temperature in a constant volume
  • · Replies 8 ·
Replies
8
Views
2K
Intuition for why escape velocity doesn't depend on angle
  • · Replies 9 ·
Replies
9
Views
2K
Space elevator minimum initial speed
  • · Replies 3 ·
Replies
3
Views
2K