R is the radius of the earth and ω is its angular velocity and gp is the value of g at the poles. The effective value of g at the latitude  λ = 60° will be equal to

Q: R is the radius of the earth and ω is its angular velocity and gp is the value of g at the poles. The effective value of g at the latitude  λ = 60° will be equal to

(a) $g_p – \frac{1}{4}R \omega^2 $

(b) $g_p – \frac{3}{4}R \omega^2 $

(c) $g_p – R \omega^2 $

(d) $g_p + \frac{1}{4}R \omega^2 $