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