For points located outside the Earth, the acceleration due to gravity decreases with distance. It is inversely proportional to the square of the distance from the center of the Earth, meaning as one moves further away, gravity becomes weaker. Specifically, this means that the gravitational force felt at a height above Earth’s surface diminishes with increasing distance from the center.

In contrast, for points inside the Earth, gravity behaves differently. The acceleration due to gravity decreases linearly as one moves closer to the center. This indicates that the gravitational pull inside the Earth is directly related to the distance from the center.

For points lying onside the earth (r > R)
gₕ/g = R²/(R + h)² = R²/r² or gₕ = gR²/r²
gₕ ∝ 1/r²

For points lying inside the earth (r < R)
gₔ = g(R – d)/R = gʳ/R or gₔ = gʳ/R
gₔ ∝ r

Latitude at a place measures how far north or south it is from the Earth’s equator. It’s expressed in degrees, starting at 0° at the equator and going up to 90° at the North and South Poles. Locations in the Northern Hemisphere have positive latitudes, while those in the Southern Hemisphere have negative latitudes.
These imaginary lines, called parallels, run horizontally around the globe. Latitude helps pinpoint a location on Earth and also influences the climate and sunlight a region gets throughout the year, playing a key role in geography and navigation.