Question

Which of the following are correct about Kepler's law?

• A. The path of the planets around the sun is elliptical, with the sun being located at one of the two foci.
  
• B. The line joining the planet and the sun sweeps equal areas in equal intervals of time.
  
• C. The cube of the average distance of a planet from the sun is directly proportional to the square of the planet's orbital time period.
  
• D. The path of the planets around the sun is circular, with the sun being located at its centre.

Answer 1

Answer: (A), (B), (C)

The correct options are
A The path of the planets around the sun is elliptical, with the sun being located at one of the two foci.

B The line joining the planet and the sun sweeps equal areas in equal intervals of time.

C The cube of the average distance of a planet from the sun is directly proportional to the square of the planet's orbital time period.


Kepler’s First Law:
The path of the planets around the sun is elliptical, with the sun being located at one of the two foci.

Kepler’s Second Law:
The line joining the planet and the sun sweeps equal areas in equal intervals of time.

Kepler’s Third Law:
The cube of the average distance of a planet from the sun is directly proportional to the square of the planet's orbital time period.
$r^3\propto T^2⟹\frac{r^3}{T^2}=constant$