Question

objects attract other objects with a force that is proportional to the product of their masses. an imaginary line from the sun to a planet sweeps out equal areas in equal time intervals. the square of the ratio of the periods of any two planets revolving about the sun is equal to their average distances from the sun. the paths of the planets are ellipses with the sun at one focus. need help? review these concept resources. read about the concept

Explanation:

The question likely asks for Kepler's laws of planetary motion. The first law states planets orbit the Sun in ellipses with the Sun at one focus; the second is the equal area law; the third is the period-distance law ($T^2 \propto r^3$). The first option describes Newton's law of gravitation, not Kepler's.

Answer:

The paths of the planets are ellipses with the Sun at one focus.
An imaginary line from the Sun to a planet sweeps out equal areas in equal time intervals.
The square of the ratio of the periods of any two planets revolving about the Sun is equal to the cube of the ratio of their average distances from the Sun. (Note: The original third option has a typo; it should be the cube of distances, but it is the only option related to Kepler's third law.)

(Assuming the question asks for Kepler's laws, these three are the correct ones. If it asks for which is NOT Kepler's, the first option is Newton's law.)

If the question is to select Kepler's laws:

• An imaginary line from the Sun to a planet sweeps out equal areas in equal time intervals.
• The square of the ratio of the periods of any two planets revolving about the Sun is equal to their average distances from the Sun. (Corrected to cube)
• The paths of the planets are ellipses with the Sun at one focus.

If it asks for which is Newton's law:

• Objects attract other objects with a force that is proportional to the product of their masses.