Because geostationary satellite ( completes it's rotation in about 24hrs).and it's rotation cycle is same as that of Earth .thus it's velocity is zero with respect to earth

Explanation:

A geostationary satellite is a satellite that orbits the Earth at the same rotational speed as the Earth, which allows it to remain in a fixed position relative to the Earth's surface. This means that the satellite appears to be stationary from the perspective of an observer on the Earth's surface.

Velocity of Geostationary Satellite:

The velocity of a geostationary satellite with respect to the Earth is zero. This is because the satellite is in a geostationary orbit, which means it is orbiting the Earth at the same angular velocity as the Earth's rotation. As a result, the satellite maintains a fixed position relative to the Earth's surface, and its velocity with respect to the Earth is zero.

Geostationary Orbit:

A geostationary orbit is a circular orbit around the Earth that is located directly above the equator. The satellite's orbital period is equal to the Earth's rotational period, which is approximately 24 hours. This means that the satellite completes one orbit around the Earth in the same amount of time that it takes for the Earth to complete one rotation on its axis.

Impact of Zero Velocity:

The zero velocity of a geostationary satellite with respect to the Earth is essential for its function. Because the satellite remains in a fixed position relative to the Earth's surface, it can be used for various purposes, such as telecommunications, weather monitoring, and television broadcasting. If the satellite had a non-zero velocity with respect to the Earth, it would not be able to remain in a fixed position and would drift away from its intended location.

Conclusion:

In conclusion, the velocity of a geostationary satellite with respect to the Earth is zero. This is because the satellite orbits the Earth at the same rotational speed as the Earth, allowing it to remain stationary relative to the Earth's surface. The zero velocity is crucial for the satellite to fulfill its intended purposes.