Gravity is maximum at the poles of the Earth.
While gravity is often thought of as a constant, its strength varies slightly across the Earth's surface. This variation is due to two primary factors: the Earth's shape and its rotation.
-
Earth's Shape: The Earth is not a perfect sphere; it's an oblate spheroid, meaning it bulges at the equator. This bulge results in points at the equator being farther from the Earth's center than points at the poles. Since gravitational force decreases with distance from the center of mass, the gravitational force is slightly weaker at the equator.
-
Earth's Rotation: The Earth's rotation creates centrifugal force, which opposes gravity. This centrifugal force is strongest at the equator because the rotational speed is greatest there. Consequently, the effective gravitational force (the force we experience as weight) is reduced more at the equator than at the poles, where the centrifugal force is minimal.
In summary, due to the Earth's shape (being an oblate spheroid) and the centrifugal force resulting from its rotation, the gravitational force, and therefore weight, is slightly greater at the poles than at the equator. This means that an object would weigh slightly more at the North or South Pole compared to the Equator.
