Question

Variation of g on the surface of earth due to axial rotation of earth by

Answer 1

The solution to this is that the Earth is an oblate spheroid rather than a sphere. Except at the equator and the poles, gravitational acceleration at a point on the surface of the Earth does not point directly downward. Instead, it has a component normal to the surface that cancels the component of the fictitious outward centrifugal normal to the surface of the Earth.