Question

Precision measurements of the acceleration due to gravity show that the acceleration is slightly different in different locations on Earth. Explain why the force of gravity is not exactly the same everywhere on Earths surface.

Answer 1

Gravity largely depends on the comparison of two objects; it's why you have the equation F= (GMm)/r^2. On Earth, you have different altitudes that, with the formula, will give different results for gravity because the radius is different everywhere. This difference on calculations, however, are seen to be miniscule. We know gravity as 9.81 m/s^2 but it might be different by thousandths or hundreds of thousandths of a decimal.

Answer 2

Answer:

Because Earth is not a perfect sphere.

Explanation:

The gravitational force acting between Earth (mass = M) and any object (mass = m) is

$F = \frac{GMm}{r^{2}}$

Where,

G = Universal gravitational constant

r = distance between center of Earth and center of the object

It is evident that the mass of Earth and object will not change with the change in location on Earth. Also value of G is also constant. The only variable is r.

We know that the Earth is not a perfect sphere it is bulged out a little around the equator and flattened near the poles because of this the Polar radius is around 21 km smaller than equatorial radius. This difference in radius creates a difference in force of gravity. Since the difference in radius is vary small the change in force is also very small.