Question

the square of the orbital period of a planet around the sun is proportional to the cube of the planet’s orbital radius. this follows the ______.
○ law of equal areas
○ law of ellipses
○ law of kepler
○ law of harmonies

Explanation:

• The law of equal areas (Kepler's second law) states that a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time, not related to period and radius.
• The law of ellipses (Kepler's first law) states that planets orbit the Sun in elliptical paths, not about period - radius relationship.
• Kepler's laws are a set of three laws. The statement "the square of the orbital period of a planet around the sun is proportional to the cube of the planet's orbital radius" is Kepler's third law, also known as the law of harmonies. The option "law of Kepler" is a general term, but the most specific and correct option here is "law of harmonies" as it directly refers to Kepler's third law which describes this period - radius relationship.

Answer:

D. law of harmonies