Calculate angular velocity of Earth so that acceleration due to gravity at 60° latitude becomes zero.
(Radius of Earth = 6400 km, gravitational acceleration at poles = 10 m/s2, cos60° = 0.5)
(A) 7.8 × 10-2 rad/s
(B) 0.5 × 10-3 radis
(C) 1 × 10-3 radis
(D) 2.5 × 10-3 rad/s
