1. Effective acceleration due to gravity at P is given as,
g’ = g – Rω2cos2θ.
2. As the value of θ increases, cos θ decreases. Therefore g’ will increase as we move away from equator towards any pole due to the rotation of the Earth.
3. At equator θ = 0°
∴ cos θ = 1
∴ g’e = g – Rω2
The effective acceleration due to gravity (g’e) is minimum at equator, as here it is reduced by Rω2
4. At poles θ = 90° cos θ = 0
∴ g’P = g – Rω2 cos θ
= g – 0
= g
There is no reduction in acceleration due to gravity at poles, due to the rotation of the Earth as the poles are lying on the axis of rotation and do not revolve.
