Question

Choose the law each sentence describes. This law relates a planet's orbital period and its average distance to the Sun. The orbits of planets are ellipses with the Sun at one focus. The speed of a planet varies, such that a planet sweeps out an equal area in equal time frames.

Answer 1

Explanation:

Kepler's has given three laws as :

1. Kepler's first law - It is also known as law of ellipses. This law states that the planets revolves around the sun in an elliptical orbit.

2. Kepler's second law - It is also known as law of equal areas. This law states that the line that connects the planet and the sun covers equal areas in equal interval of time.

3. Kepler's third law - It is also known as law of law of harmonics. This law states that the square of orbital time period is directly proportional to the cube of the average distance from the sun i.e. $T^2\propto a^3$  

Answer 2

These are the Kepler's laws of planetary motion.

This law relates a planet's orbital period and its average distance to the Sun. - Third law of Kepler.

The orbits of planets are ellipses with the Sun at one focus. - First law of Kepler.

The speed of a planet varies, such that a planet sweeps out an equal area in equal time frames. - Second law of Kepler.