Question

what are the Kepler's law of planetary motion ? ​

Answer 1

Question

what are the Kepler's law of planetary motion ?

Answer

There are three laws given by Kepler ;

the Kepler law of planetary motion states that ;

• the planet moves in elliptical Orbit around the sun with the sun at one of two foci of the elliptical orbit .

Explanation :- this law means that the orbit of a planet around the sun is an eclipse and not an exact circle . an elliptical path has to foci and the sun is at one of the two foci of the elliptical path .

• each planet revolves around the sun in such a way that the line joining the planet to the sun sweeps over equal area in equal interval of time .

Explanation :- we know that a planet moves around the sun in elliptical Orbit with sun at one of its focus Now since the line joining the planet and the sun sweets over equal area in equal interval of time it means that a planet moves faster when it is closer to stand and move slowly when it is farther from the Sun .

• the cube of the main distance of a planet from the sun is directly proportional to the square of time it takes to move around the sun .

Explantion :-

r^3 is directly proportional to T ^2

=> r^3 = constant × t^2

=> r^3/t^2 = constant

where

• r means distance of planets from the Sun .
• t means time period of the planet around the sun .

Answer 2

Kepler's laws of planetary motion are:-

Kepler's first law(Law of Orbit): All planets revolve around the sun in elliptical orbits. Sun is at one of the focii of ellipse.

Kepler's second law (Law of Areas): The line joining the planet and the sun sweeps equal areas in equal intervals of time.

Area of sp₁p₂ = area of s p₃ p₄, when time taken from p₁ to p₂ is equal to time taken from p₃ to p₄.

Kepler's third law (Law of Periods): The cube of the mean distance of a planet from the sun is proportional to the square of its orbital period T.

r³∝T² or r³/T² = Constant

Some Extra Information:-

Tycho Brahe,in 16th century observed planetary motion for 20 years by simple instruments, as telescope was not invented at that time! Before the death of Tycho,he handed over the collected data to one of his students Johannes Kepler so that it could be published. Kepler,while analysing the data came to three important conclusions which were later known as 'Kepler's law of planetary motion'.