Question

Two satellites of masses 50 kg and 100 kg revolve around the earth in circular orbits of radii 9R and 16R. What is the ratio of speeds of the two satellites?

(a) 3:4

(b) 4:3

(c) 9:16

(d) 16:9

I had been asked this question during an interview for a job.

The origin of the question is Gravitation in chapter Gravitation of Physics – Class 11

Answer 1

Right choice is (b) 4:3

The explanation: Orbital velocity is inversely proportional to the square root of the orbital radius.

Hence;

v1 : v2 = 16^1/2 : 9^1/2

 = 4 : 3