Question

Why is the value of g greater at the poles?

Answer 1

Hint: We know that the gravitational force is inversely proportional to the square of the distance from the earth's center. The length from the poles to the center of the earth is smaller than the distance from the equator to the earth's center. Therefore the acceleration due to gravity is more significant at the poles than at the equator.

Complete step-by-step solution:
Formula for acceleration due to gravity is given by:
$g = \dfrac{GM}{R^{2}}$
The value of the gravity at the pole is more significant than at the equator because the poles are nearer to the earth's center due to the earth's oblateness. This statement seems misleading in that it attributes significance to the center of mass in such situations and seems to imply a simple distance connection.
The earth's radius at poles is the least, so acceleration due to gravity will be highest at poles because g is inversely proportional to the square of the radius.
Gravitational force is always inversely proportional to the distance between the earth's center and the object under study. The earth's shape is not in the formation of a perfect sphere.
Earth has a bulging at its equator due to the centrifugal force produced by the earth's rotation. The distance of poles is smaller from the center of the earth than the distance separating the center of earth & the equator.
The measured value is more significant because the earth's density is not uniform but rises towards the center.

Note:Earth is not a complete sphere. It is levelled at the poles and swelled at the equator. The centrifugal force generated by the earth's rotation results in the swelling of the earth at the equator. Also, net acceleration due to gravity is influenced by centrifugal force due to the earth's rotation.