Question

why does the weight in polar regions differ than the normal weight

Answer 1

The Earth is an oblate spheroid, i.e. a squished sphere. It's squished from top to bottom so that its fattest around the equator. What that means is that the radius of the Earth is greatest at the equator and gets progressively smaller as you move toward the poles. With that hand, look at the law of gravitational force:\[F=G \frac{ M _{E}m }{ r ^{2} }\]where F is the force; G is the gravitational constant; ME is the mass of the Earth; m is the mass of something on the surface of the Earth; and r is the radius at that point on Earth. What I told you about the shape of the Earth coupled with this equation should make it obvious why someone would weigh more at one of the poles than they would at the Equator.

Answer 2

Do you see why that is?

Answer 3

radius is uniform ?

Answer 4

The radius of Earth is not uniform. The attached picture shows an exaggeration of what Earth looks like. See how its radius is longer at the equator (x-axis intercepts) than it is at the poles (y-axis intercepts)?

Answer 5

Now look at the force equation I gave you. What happens when to the force when r gets really big? What happens to the force when r gets really small?

Answer 6

oh ok, force increases?

Answer 7

When r gets big, the force decreases. When r gets small, the force increases.

Answer 8

yes nd hw wuld dt relate to the weight, i mn is dere ny equation

Answer 9

Weight is the force of gravity on your mass, so F=W.

Answer 10

oh okay thanks

Answer 11

You're welcome.

Answer 12

So called normal weight is taken at about 45° latitude.
When you are at the poles, two effects add up:
- you are closer to Earth's centre (refer to Psi²'s explanation)
- no centrifugal force is acting at the poles since you are on Earth's axis of rotation.

Keep in mind that, unlike gravitational force, weight \(does\) take inertial forces into account.