Question

Two satellites A and B go round a planet p in circular orbits having radii 4R and R respectively if the speed of the satellite A is 3V, the speed if satellite B will be 

(A) 12V 

(B) 6 V 

(C) 4/3 V 

(D) 3/2 V

Answer 1

Correct option: (B) 6 V

Explanation:

V = √(GM / R)

(V_A / V_B) = √(R_B / R_A)

= √(R / 4R) = (1/2)

2V_A = V_B -------- as (B) 6 V_A = 3V

V_B = 2 × 3V = 6V