Question

Two artificial satellites I and II have circular orbits of radii R and 2R, respectively, about the same planet. The orbital velocity of satellite I is v. What is the orbital velocity of satellite II? 

(A) v/2

(B) v/√2 

(C) v 

(D) √2v

(E) 2v

Answer 1

Correct option  (B) v/√2

Orbital speed is found from setting GMm/r² = mv²/r which gives  v = √(GM/r) where M is the object being orbited.