alleryStart learning →Why does the moon not trace a perfectly smooth circle around the sun?
APulled by both Earth and the sun, not always additive
BPulled only by Earth's gravity, never the sun's
CPulled only by the sun's gravity, never Earth's
DGravity has no effect on its path at all
Answer & Solution
Correct answer: A. Pulled by both Earth and the sun, not always additive
1. The moon feels gravitational pulls from both Earth and the sun simultaneously.
2. Depending on where the moon sits in its orbit, those two pulls sometimes add and sometimes partly cancel.
3. That changing combination is what keeps the moon's path around the sun from being a smooth, simple circle.
_Source: OpenStax Physics (CC BY 4.0), Ch 7 "Newton's Law of Gravitation", section 7.2 Newton's Law of Universal Gravitation and Einstein's Theory of General Relativity_
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