Can you explain why I weigh less at the Equator than at the North Pole?

Question

No homework. Explain please. Thanks.

Answer 1

The two reasons (centripetal acceleration and less g due to increased radius at the equator) have been given in the answers above, but only one answer referred to both of them, and then only suggested that it was one or the other. Well it's the combined effect of the two that reduces your equatorial weight. And (this shouldn't be too surprising) the reason Earth's equatorial radius is greater than its polar radius is in fact centripetal acceleration applied to the earth itself. Earth's huge size causes the solid materials like rock that it's made of, that are rigid on a smaller scale, to behave more like a thick liquid and be distorted in the direction of the centripetal acceleration.
Note that you won't see your weight difference on a weight-balance type scale, since those weights are subject to the same centripetal and gravitational accelerations as you are. Only a spring-based scale can measure these differences.

Answer 2

The earth rotates about the axis passing through the North and South poles.

If we drop a line from any point on the earth’s surface perpendicular to the axis of rotation (note that the line is not passing through the center of the earth) we can note that the distance of the point is zero at the pole and is the maximum at the equator.

The centripetal force due to rotation is mv^2 / h or mhω^2. (ω is the same for all points)

Therefore this force is zero at the pole and is the maximum at the equator.

This is all about the centripetal force.

Considering the weight of an object, what we call as weight is the reaction of the earth that acts on us.

Imagine the earth is not rotating about its axis. The gravitational pull will be there and is equal to GM/ R^2 for each kg of object. Irrespective of the point on the surface, this force will be acting on every object on the surface and will be pointed toward the center of the earth. The force on each kilogram will be the same at the equator and at the poles and at any point on the surface of earth.

Since this force pulls us toward the center of the earth, we are pressing the ground with this force and as a reaction force; the ground (not the earth) pushes us up. We call this force as our weight.

But objects on the equator are having the maximum rotational speed or centripetal force, because of earth’s rotation. It is not hard to see that the objects will not press the earth by this amount of force. [Objects in circular motion will not move along the radius of the circle]

Since the pressing force is reduced, the weight is reduced. We will not be pressing the springs in the weighing machine if we are in equator than while we were at Poles.


If one’s speed is such that mhω^2 = mg then he will not press at all and his weight is zero.

In the equator, the reduction of weight is so small that we can neglect it for civil life.

Answer 3

ultimate reasoning. it is the area you pass incorrect. An merchandise on the equator is moving in a super circle (the Earth is rotating), an merchandise on the north pole isn't moving in around action. the load of the guy or female on the equator equals the gravitational pull (mg) minus the centrifugal rigidity with regard to the around pass (mv^2/r). for that reason the comparable merchandise weighs much less on the equator than on the north pole. be conscious: the extremely disadvantage is slightly extra problematic. The Earth should not be a merely right sphere, north pole is in the direction of the middle than a element on the equator.. this is the motive for "extra desirable weight" on the north pole.

Answer 4

The shape of the earth is like an orange not exactly round. That means the distance between a point on the equater and the centre of the earth is more than the distance between North Pole and the centre of the earth (gravity). Right?
So standing at a point on the equater means you are standing further away from the centre of gravity. Therefore the gravitional pull on you become less in comparison to when you are standing at a point in the North Pole. Thats why you weigh less.
The further away you go from the surface of the earth, the lesser you weigh. At a point outside the gravitional field of the earth, you become weightless.

Answer 5

because of centripetal acceleration you will weigh a tiny amount less at the equator than at the poles. Try not to think of centripetal acceleration as a force though; what's really going on is that objects which are in motion like to go in a straight line and so it takes some force to make them go round in a circle. So some of the force of gravity is being used to make you go round in a circle at the equator (instead of flying off into space) while at the pole this is not needed. The centripetal acceleration at the equator is given by 4 times pi squared times the radius of the Earth divided by the period of rotation squared (4*pi2*r/T2). The period of rotation is 24 hours (or 86400 seconds) and the radius of the Earth is about 6400 km. This means that the centripetal acceletation at the equator is about 0.03 m/s2 (metres per seconds squared). Compare this to the acceleration due to gravity which is about 10 m/s2 and you can see how tiny an effect this is - you would weigh about 0.3% less at the equator than at the poles!

Answer 6

If this is fact, one would assume it is because of the centripetal force pushing you out due to the rotation of the earth. Either that, or the earth is not round, and the equator is further away from the centre of the earth than the North Pole is. The further away from the centre you get, the less the force of gravity is.
Then again, maybe you lost weight on your way to the equator.

Answer 7

because the earth is oval in shape.(hope u know this) the north and south pole is more near to the earth core, so the gravitational force is more strong at the poles. as a result, the object at the poles will expirience grater gravitationla force, so the weight is more than the weight at equator.

Answer 8

Because at the equator you'd be wearing a bikini whereas at the north pole you'd be bundled up like a freakin' Eskimo. I don't have a clue what that putz Ozzie's babbling about, I think he's read too many science books or something. Jeez man, lay of the pi before your circumference reaches critical mass and you end up looking like a hypotenuse.

Answer 9

how much you weigh is determined by the pull of gravity from the earth, the pull of gravity is determined by how much mass of the earth is directly beneath you.

The earth is not a perfect sphere. if you drill through the earth from equator to equator, itll will take longer than drilling from pole to pole.

at the equator there is therefor more mass directly beneath you. and you thus weight slightly more. the difference is hardly noticable though.

Answer 10

the earth bulges at the equator and flat at the poles. the rule is " the farther you are from the center (core) of the earth the less you weigh. its in the fundamentals of gravity laws of gravity by newton.