# Objects weigh less at the equator?

**URL:** <https://boards.straightdope.com/t/objects-weigh-less-at-the-equator/9680>\
**Category:** Factual Questions\
**Created:** [April 3, 2000, 3:45pm UTC](https://boards.straightdope.com/t/objects-weigh-less-at-the-equator/9680 "2000-04-03T15:45:00Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![fireftr49](https://avatars.discourse-cdn.com/v4/letter/f/48db29/32.png) [@fireftr49](https://boards.straightdope.com/u/fireftr49)\
**Post date:** [April 3, 2000, 3:45pm UTC](https://boards.straightdope.com/t/objects-weigh-less-at-the-equator/9680/1 "2000-04-03T15:45:00Z")

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Does an object weigh less at the equator than the same object would at the north pole? Put another way, does the centrifugal force at the equator (from our spinning earth) counteract gravity to any measurable degree? I would expect the force to be greater at the equator and less at the poles, while gravity is constant. My apologies if this has been already covered.

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**Author:** ![KarmaComa](https://avatars.discourse-cdn.com/v4/letter/k/e36b37/32.png) [@KarmaComa](https://boards.straightdope.com/u/KarmaComa)\
**Post date:** [April 3, 2000, 4:11pm UTC](https://boards.straightdope.com/t/objects-weigh-less-at-the-equator/9680/2 "2000-04-03T16:11:00Z")

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> [@](#):
>
> Originally posted by fireftr49:  
> **Does an object weigh less at the equator than the same object would at the north pole? Put another way, does the centrifugal force at the equator (from our spinning earth) counteract gravity to any measurable degree? I would expect the force to be greater at the equator and less at the poles, while gravity is constant. My apologies if this has been already covered.**

Yes, objects weigh less at the equator… very slightly less. I remember we calculated how fast the earth would have to rotate to produce weightlessness at the equator, and it was something like one hour per day.

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**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\
**Post date:** [April 4, 2000, 1:46am UTC](https://boards.straightdope.com/t/objects-weigh-less-at-the-equator/9680/3 "2000-04-04T01:46:00Z")

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centrifugal force aside, the radius of the earth at the equator is greater than at the pole so, being farther from the center of mass (by about 20 miles I believe) the force of gravity is smaller.

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**Author:** ![eggo](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@eggo](https://boards.straightdope.com/u/eggo)\
**Post date:** [April 4, 2000, 3:34am UTC](https://boards.straightdope.com/t/objects-weigh-less-at-the-equator/9680/4 "2000-04-04T03:34:00Z")

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but you’re forgeting that centrifugal force is the \<i\>reason\</i\> that the earth is bigger at the equator. if you were to put it “aside” the planet would (although not instantly) spring back into a spherical shape.

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eggo

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