Question

The speed of a geostationary satellite relative to a person on the earth is
A. Zero
B. $2 km/s$
C. $10 km/s$
D. $8 km/s$

Answer 1

Hint: A satellite that revolves around the earth with the same angular speed as of earth and in the same direction of the earth.Geostationary satellites are a key tool for scientists to monitor and observe the Earth's atmosphere. They are called geostationary due to their movement. Geostationary satellites orbit around the Earth at the same rate as the Earth rotates so that the satellites are over the same spot on Earth all the time.

Complete answer:
Geostationary satellite is a type of satellite developed to revolve around the earth from west to east direction with a period of revolution equal to 24 hours in a circular orbit coplanar and concentric with the equatorial plane of the earth and its relative velocity with respect to the earth is zero.

The person (observer) is on the surface of earth and its relative velocity with respect to the earth is zero. Thus, the relative velocity of the geostationary satellite relative to a person on the earth is also zero.

Thus, option A is correct.

Additional information:
The following are the uses of the geostationary satellite:
1. It is used in communicating radio, radio, television and mobile signals all over the world. It acts as a reflector of the signals.
2. It is used in studying the higher region of the atmosphere.
3. It is used in predicting the weather of the earth.
4. It is used in evaluating the shape and size of the earth planet.

Note:The mandatory conditions for a geostationary satellite are that it should revolve in a circular orbit coplanar and concentric with the equatorial plane of the earth, its sense of rotation should be same as of earth, it should revolve at a height of approximately 36000 km above the surface of the earth.