Question

Two planets (each having mass m) revolve around a stationary star ( of mass M ) in a circle of radius r. The two planets are always on opposite side of the star (i.e. they are diametrically opposite and always having separation 2r ). The orbital ** T of the planets is of the form T = 2π √r3/GM,What is the value of M' ?

(A) M- m/2

(B) M- m/4

(C) M

(D) M+m/4

Answer 1

Correct option M+m/4

Explanation:

Here, M’ is the mass of the central body which can be calculated as the sum of the masses of two planets and central body.