Both earth and moon are subjected to the gravitational force of the sun. as observed from the sun, the orbit of the moon

Options

A. will be elliptical
B. will not be strictly elliptical because the total gravitational force on it not central
C. is not elliptical but will necessarily be a closed curve.
D. deviates considerably from being elliptical due to influence of planets other than earth.

Answer

To solve the problem of how the Moon's orbit appears from the Sun, we need to analyze the forces acting on the Moon and how they affect its motion. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Forces Acting on the Moon
The Moon is influenced by two main gravitational forces:
- The gravitational force exerted by the Sun (Fs).
- The gravitational force exerted by the Earth (Fe).

### Step 2: Analyze the Motion of the Earth
The Earth revolves around the Sun in an elliptical orbit due to the gravitational attraction of the Sun. This is in accordance with Kepler's laws of planetary motion.

### Step 3: Analyze the Motion of the Moon
As the Earth revolves around the Sun, the Moon orbits the Earth. From the perspective of an observer on the Sun, the Moon's motion is not solely determined by the gravitational force from the Sun, but also by the gravitational force from the Earth.

### Step 4: Determine the Resultant Force on the Moon
The net gravitational force acting on the Moon is the vector sum of the forces from the Sun and the Earth. Since these forces are not aligned (one is directed towards the Sun and the other towards the Earth), the resultant force (Fm) on the Moon will not point directly towards the Sun.

### Step 5: Conclude the Nature of the Moon's Orbit
Because the resultant force on the Moon is not directed towards the center of the Sun, the Moon's orbit cannot be strictly elliptical. In an elliptical orbit, the net force must always point towards the focal point of the ellipse (in this case, the Sun). Since the Moon's net force is influenced by the Earth, its path will deviate from a perfect ellipse.

### Final Conclusion
The Moon's orbit, as observed from the Sun, will not be strictly elliptical due to the influence of the Earth's gravitational force. Therefore, the correct answer to the question is that the orbit of the Moon will not be strictly elliptical because the total gravitational force on it is not central.

---