To solve this problem, we need to understand the relationship between the distance of a planet from the sun and its orbital speed. According to Kepler's laws of planetary motion and the principles of gravitation, the closer a planet is to the sun, the stronger the gravitational force exerted on it by the sun. This stronger force results in a higher orbital speed.
Given the distances:
- Planet W is 1.5 AU from the sun
- Planet X is 0.723 AU from the sun
Among the given multiple-choice answers:
1. "Planet X, because the sun pulls it with a greater force": This statement is correct. Since Planet X is closer to the sun, it experiences a greater gravitational pull, which results in a faster orbital speed.
2. "Planet W, because the sun pulls it with a greater force": This statement is incorrect. Planet W is farther from the sun and therefore experiences a weaker gravitational pull.
3. "Planet W, because the gravitational force is weakened by distance": This is true but irrelevant to the question of which planet revolves faster.
4. "Planet X, because the gravitational force is strengthened by distance": This is a correct explanation. Planet X being closer to the sun experiences a stronger gravitational force, causing it to revolve faster.
Therefore, the best explanation is:
Planet [tex]\( X \)[/tex], because the gravitational force is strengthened by distance.
