A satellite revolving around the earth is

Options

A. an inertial frame
B. a non-inertial frame
C. both an inertial and non-inertial frame
D. inertial only when the height of the satellite is high

Answer

To determine whether a satellite revolving around the Earth is an inertial frame, non-inertial frame, both, or neither, we can follow these steps:

### Step 1: Define Inertial and Non-Inertial Frames
- An **inertial frame of reference** is one in which an object not acted upon by a net force moves at a constant velocity (including being at rest). In other words, it follows Newton's first law of motion.
- A **non-inertial frame of reference** is one that is accelerating or rotating. In such frames, objects appear to experience fictitious forces (like centrifugal force).

### Step 2: Analyze the Motion of the Satellite
- A satellite in orbit around the Earth is in continuous motion along a circular path. This means it is constantly changing direction, which implies that it is experiencing acceleration due to the gravitational pull of the Earth.

### Step 3: Determine the Frame of Reference
- Since the satellite is moving in a circular path and is subject to a centripetal force (the gravitational force from the Earth), it is not at rest or moving with a constant velocity. Therefore, it does not meet the criteria for an inertial frame.

### Step 4: Conclusion
- Based on the definitions and the analysis of the satellite's motion, we conclude that the satellite is in a **non-inertial frame of reference** because it is accelerating as it revolves around the Earth.

### Final Answer
The correct answer is: **non-inertial frame**.

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