What is the orbital speed of the second satellite?
February 23, 2010 by
Filed under Satellite
A satellite is in a circular orbit around an unknown planet. The satellite has a speed of 1.60 104 m/s, and the radius of the orbit is 5.40 106 m. A second satellite also has a circular orbit around this same planet. The orbit of this second satellite has a radius of 8.80 106 m. What is the orbital speed of the second satellite?
V2 R2 = V1 R1
V2 = V1 R1 / R2
V2 = 1.6 X10^4 x 5.4 /8.8
V2 = 0.981 x10^4 m/s
For the two satellites to both be in orbit around the same planet, their centrifugal forces (the forces tending to pull them off into space) must equal the gravity of the planet and must be the same. The centrifugal force is equal to their angular speed times the radius of their path. Therefore,
(1.60 104 m/s) x (5.40 106 m) = Speed x (8.80 106 m)
Solve for “Speed”.
Note: This assumes the radius of the orbit given is from the center of the planet, not from the surface of the planet.