Satellites in communication

Which of the following is the appropriate unit for angular velocity, ω?

• s^-1

• m s^-1

• kgms^-1

• rad s^-1

Each of five satellites makes a circular orbit about an object that is much more massive than any of the satellites. The mass and orbital radius of each satellite are given below. Which satellite has the greatest speed?

• A

• B

• C

• D

• E

Why are VHF, UHF, and microwave signals used in satellite communication?

• more bandwidth

• more spectrum space

• are not diffracted by the ionosphere

• Economically viable

A geostationary satellite orbits around earth once

• per month

• per week

• per day

• per hour

Most satellites operate in which frequency band?

• 30 to 300 MHz

• 300 MHz to 3 GHz

• 3 GHz to 30 GHz

• Above 300 GHz

Which one is NOT one of the reasons why satellites at 6/4GHz are preferred to sky waves?

• Long-distance communication using sky waves is unreliable due to changing ionospheric conditions

• The sky waves band is already filled by existing broadcasting stations

• Greater bandwidth in the GHz range can carry more information

• It is much cheaper than using broadband

A satellite of mass m and speed v moves in a stable, circular orbit around a planet of mass M. What is the radius of the satellite's orbit?

• A

• B

• C

• D

• E

Two artificial satellites, 1 and 2, orbit the Earth in circular orbits having radii R₁ and R₂, respectively, as shown above. If R₂ = 2R₁, the accelerations a₂ and a₁ of the two satellites are related by which of the following?

• a₂ = 4a₁

• a₂ = 2a₁

• a₂ = a₁

• a₂ = a₁/2

• a₂ = a₁/4

A satellite moves in a stable circular orbit with speed v_o at a distance R from the center of a planet. For this satellite to move in a stable circular orbit a distance 2R from the center of the planet, the speed of the satellite must be B

• A

• B

• C

• D

• E