Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: If we move from poles to equator, the direction of acceleration due to gravity of earth always points towards the center of earth without any variation in its magnitude.
Reason R: At equator, the direction of acceleration due to gravity is towards the center of earth.
In the light of above statements, choose the correct answer from the options given below.
Answer: (D) Assertion is false but reason is true.
Because of the earth's rotation, the effective $g' = g - \omega^2R\cos^2\lambda$ changes in magnitude with latitude $\lambda$, and between the poles and the equator its direction is slightly off the centre. So A is false.
At the equator the centrifugal term is directly opposite to gravity, so $g'$ still points towards the centre. R is true.
Solution by Sreeraj P, M.Sc Physics