Human weight changes on your location

[Quasar44]

Final science post

A person living on the equator is several pounds less weight that someone living on the poles

Why

The earth is rotating much faster on the equator than the poles
This faster rotation simply means it’s trying to fling you off the planet and your gravitational pull becomes weaker

Clearly it’s not rotating fast enough or you would be in orbit

 

[norwegen]

That settles it. My next diet will consist of eating Brazilian food.

In Brazil.

 

[Polishprince]

Interesting. I can see why Dr. Nowzaraden has his bariatric clinic in the southern US in Houston instead of Montana or Maine.

A lot more encouraging to his patients, being closer to the equator.

 

[Moonglow]

Interesting. I can see why Dr. Nowzaraden has his bariatric clinic in the southern US in Houston instead of Montana or Maine.

A lot more encouraging to his patients, being closer to the equator.

The mass remains the same, by Led Zepplin...

 

[ReinyDays]

A person living on the equator is several pounds less weight that someone living on the poles

True ...

The earth is rotating much faster on the equator than the poles

Also true ...

This faster rotation simply means it’s trying to fling you off the planet and your gravitational pull becomes weaker

This is a common urban myth ... and is false I'm afraid ... you're saying the weight difference is caused by the centrifugal force, which is considered a pseudo-force or sometimes a fictitious force ... meaning it performs no work ... and it has no effect on the real force of gravity ... thus no effect on weight ...

The weight difference is caused by being further from the center-of-gravity at the equator than at the poles ... gravity is inversely proportional to the square of distance ... and the Earth bulges at the equator due to hydrostatic equilibrium ... which is strictly an effect of gravity ... this weight difference would be the same whether we're rotating or not ...

 

[Mr Natural]

And the difference between high and low tide is less at the equator than at the poles.

 

[Blues Man]

When you fly time actually slows down for you

 

[ReinyDays]

If we shrunk the Earth to the size of a billiard ball ... it would meet International Championship rules for roundness ... the Earth doesn't bulge very much at her equator ...

 

[Quasar44]

And the difference between high and low tide is less at the equator than at the poles.

Funny thing is that the tides are only an illusion that its moving in and out !! What is happening is that they’re fixed and you’re rotating around them as earth moves

 

[Quasar44]

A person living on the equator is several pounds less weight that someone living on the poles

True ...

The earth is rotating much faster on the equator than the poles

Also true ...

This faster rotation simply means it’s trying to fling you off the planet and your gravitational pull becomes weaker

This is a common urban myth ... and is false I'm afraid ... you're saying the weight difference is caused by the centrifugal force, which is considered a pseudo-force or sometimes a fictitious force ... meaning it performs no work ... and it has no effect on the real force of gravity ... thus no effect on weight ...

The weight difference is caused by being further from the center-of-gravity at the equator than at the poles ... gravity is inversely proportional to the square of distance ... and the Earth bulges at the equator due to hydrostatic equilibrium ... which is strictly an effect of gravity ... this weight difference would be the same whether we're rotating or not ...

Yes the further from the center of mass ..you receive less gravity force

 

[Fort Fun Indiana]

you're saying the weight difference is caused by the centrifugal force, which is considered a pseudo-force or sometimes a fictitious force ... meaning it performs no work ... and it has no effect on the real force of gravity ... thus no effect on weight ...

while it is an "apparent force", the actual force and work are done by gravity. it has to correct your path through space to keep you standing on the ground. yes, you do, in fact, "weigh less", if you stand on a scale that is sitting on the surface of the planet at the equator. Now, if you placed the scale perpendicular to the surface of the earth and could stand on it, the weight it recorded would not change (yes, technically it would be zero, but it would always be zero. And if there were a force that did cause weight on the scale, it would remain constant as well)..

 

[Fort Fun Indiana]

Yes the further from the center of mass ..you receive less gravity force

Yes, but that is a different discussion. If the earth were a perfect sphere, you would still weigh less at the equator than at the poles, per a scale sitting on the surface.

 

[Quasar44]

Yes the further from the center of mass ..you receive less gravity force

Yes, but that is a different discussion. If the earth were a perfect sphere, you would still weigh less at the equator than at the poles, per a scale sitting on the surface.

Because the rotational speed is faster at the equator; hence , the planet is trying to “ fling you off more “

 

[Fort Fun Indiana]

hence , the planet is trying to “ fling you off more “

Basically, yeah. You have more inertia in the direction tangential to the point on which you stand. As such, with the force of gravity being constant (as your mass is constant), it only does the same amount of work on you, no matter your inertia. With more inertia tangential to the surface, more work is required to maintain the same downward force perpendicular to the surface. As the force of gravity remains constant instead, this downward force is then reduced.

 

[Fort Fun Indiana]

One way to grasp this idea:

If the Earth were rotating quickly enough that objects at the equator were moving (in a direction tangential to the surface) at Earth's escape velocity, everything on the surface at the equator that was not tied down would just continue on that tangential path right into outer space.

(You would appear, to an observer at a fixed point on the surface, to float up into the sky in a curved path that bent to the west, until you disappeared behind the horizon.)

Yet, this tangential velocity component at the poles would still be zero. You would weigh your normal weight at the poles, and you would weigh "zero" on a scale at the equator.

 

[Dusty]

Final science post

A person living on the equator is several pounds less weight that someone living on the poles

Why

The earth is rotating much faster on the equator than the poles
This faster rotation simply means it’s trying to fling you off the planet and your gravitational pull becomes weaker

Clearly it’s not rotating fast enough or you would be in orbit

8 year olds can look up all sorts of neat things on the internet

 

[ReinyDays]

... per a scale sitting on the surface.

The scale is also under acceleration, so its readings would not be an inertial frame-of-reference ... if we don't take this into consideration, then the centrifugal force will appear giving the illusion of less weight ...

 

[Quasar44]

... per a scale sitting on the surface.

The scale is also under acceleration, so its readings would not be an inertial frame-of-reference ... if we don't take this into consideration, then the centrifugal force will appear giving the illusion of less weight ...

In a free fall from orbit to surface : you would be weightless and have zero weight

 

[Fort Fun Indiana]

The scale is also under acceleration, so its readings would not be an inertial frame-of-reference

Very true, in that the scale is also under acceleration. I admit, in my comments, i ignored this. But i ignored it for a reason. Scales are calibrated to register force. As it is true in our scenario that the scale also has the same inertia as the person on itt, it is not it is not doing extra work on the person at the equator. They are in the same frame, moving identically. Both will experience less.force in the downward component. Calibrated scales register force.

 

[Fort Fun Indiana]

In a free fall from orbit to surface : you would be weightless and have zero weight

*assuming the scale's frame of reference is the same as your own

Given recent confusion, i think it bears repeating.