Factors Affecting Acceleration Due to Gravity
( i) Shape of Earth Acceleration due to gravity g & infi; 1 / R 2 Earth is elliptical in shape. Its diameter at poles is approximately 42 km less than its diameter at equator.
Therefore, g is minimum at equator and maximum at poles.
( ii) Rotation of Earth about Its Own Axis If ω is the angular velocity of rotation of earth about its own axis, then acceleration due to gravity at a place having latitude λ is given by
g’ = g – Rω 2 cos 2 λ At poles λ = 90 ° and g’ = g
Therefore, there is no effect of rotation of earth about its own axis at poles.
At equator λ = 0 ° and g’ = g – Rω 2