How much faster would the Earth need to spin...

DRZ

DRZ

DRZ

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...for zero mavity at the Equator?

If I'm correct (which I think I am), the fact we are rotating with the Earth means that Newton wants us to fly off into space. The attraction between our mass and the Earth (mavity) prevents this from happening but there must be a point at which the forces are equal, which means Zero mavity (lets ignore the Sun and the Moon and any other celestial bodies which would exert sufficient influence on this).

Roughly how much faster would the Earth need to spin for this to be the case? I've long since forgotten the relevant equations from my A-Level physics classes :p
 
About 17 times faster than it currently does, assuming we take atmosphere and temperature out of the equation.

/Salsa
 
I haven't done physics for a while so this is probably wrong
a=v^2/r
ar=v^2

radius of the earth=6 378.1 km ( not a perfect sphere though)
acceleration on the surface = 9.8 m/s^2
9.8*6378*10^3=v^2
62504400=v^2
7906 m /s =v
So you it would need to spin 7906 meters per second faster.
 
RomanNose said:
I haven't done physics for a while so this is probably wrong
a=v^2/r
ar=v^2

radius of the earth=6 378.1 km ( not a perfect sphere though)
acceleration on the surface = 9.8 m/s^2
9.8*6378*10^3=v^2
62504400=v^2
7906 m /s =v
So you it would need to spin 7906 meters per second faster.
Click to expand...

Is that Klingon? :)
 
Dimple said:
So if the Earth spins once in every 24 hours how many revolutions would it need to spin at for us to reach zero mavity?
Click to expand...

Once every 84 minutes to reach terminal escape velocity.

Alternatively if the earth stopped spinning suddenly then the sudden removal of the centripetal force (mavity) would cause us all to shoot off into space.

/Salsa
 
Salsa said:
Alternatively if the earth stopped spinning suddenly then the sudden removal of the centripetal force (mavity) would cause us all to shoot off into space.

/Salsa
Click to expand...

bigbang-bitchplease.jpg
 
Salsa said:
Once every 84 minutes to reach terminal escape velocity.

Alternatively if the earth stopped spinning suddenly then the sudden removal of the centripetal force (mavity) would cause us all to shoot off into space.

/Salsa
Click to expand...

Eh? No it wouldn't. It could be pretty bad news depending on what you mean by suddenly. If you mean instantaneously, then the surface speed (at the equator) goes from about 1000 mph to 0. From our point of view it would be as if the ground suddenly started moving west under our feet at about 1000 mph (at the equator) like some insane treadmill. Not much in the way of buildings, etc would survive that. Of course that effect would reduce down to 0 towards the poles. An eskimo might just fall over :)
 
Liampope said:
Eh? No it wouldn't. It could be pretty bad news depending on what you mean by suddenly. If you mean instantaneously, then the surface speed (at the equator) goes from about 1000 mph to 0. From our point of view it would be as if the ground suddenly started moving west under our feet at about 1000 mph (at the equator) like some insane treadmill. Not much in the way of buildings, etc would survive that. Of course that effect would reduce down to 0 towards the poles. An eskimo might just fall over :)
Click to expand...

Yes thats more what I was getting at. Assuming a near instantaneous stop in rotation your velocity relative to the earth's surface would go from 0 m/s to the current rotational velocity of the earth. You would continue to move in the direction at which you were moving relative to the earth's surface at the moment it stopped along a plane perpendicular to its axis of rotation.

/Salsa
 
Liampope said:
Eh? No it wouldn't. It could be pretty bad news depending on what you mean by suddenly. If you mean instantaneously, then the surface speed (at the equator) goes from about 1000 mph to 0. From our point of view it would be as if the ground suddenly started moving west under our feet at about 1000 mph (at the equator) like some insane treadmill. Not much in the way of buildings, etc would survive that. Of course that effect would reduce down to 0 towards the poles. An eskimo might just fall over :)
Click to expand...

But what if it slowly came to a halt over say a 24 hour period?
 
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