# he masses and radii of the earth and moon are M1 , R1 and M2 , R2 respectively. Their centres are distance d apart. The minimum velocity with which a particle of mass m should be projected from a point midway between their centres so that it escapes to infinity is

Q: The masses and radii of the earth and moon are M1 , R1 and M2 , R2 respectively. Their centres are distance d apart. The minimum velocity with which a particle of mass m should be projected from a point midway between their centres so that it escapes to infinity is

(a) $2\sqrt{\frac{G}{d}(M_1 + M_2)}$

(b) $2\sqrt{\frac{2G}{d}(M_1 + M_2)}$

(c) $2\sqrt{\frac{G m}{d}(M_1 + M_2)}$

(d) $2\sqrt{\frac{G m}{d (R_1 + R_2)}(M_1 + M_2)}$