Keplers Laws Of Motion

Question 1

What is K1

Answer 1

K1 is :

Each planet moves in an ellipse with sun at focus

Question 2

What is K2

Answer 2

K2 is:

Areas swept out by radius vector from sun to planet in equal times are equal

Question 3

What is period of revolution

Answer 3

Period of revolution is mean time for a body (planet) to complete a revolution about another (sun)

Question 4

What is K3

Answer 4

K3 is:
If T is period of revolution of a planet then
T^2 = ca^3 where
A = l/(1-e^2) (semi-major axis)
C is constant independent of planet

Question 5

What is the orbit of a planet in polar coordinates

Answer 5

Orbit of a planet in polar coordinates is:

R = L/(1+ecos(theta)) where L and e are different for each planet

Answer 6

K2 implies dA/dt (change in area swept out w.r.t time) is a constant so 0.5 * r^2*theta. = h (constant) = angular momentum

Question 7

What is period of revolution T equal to

Answer 7

Period of revolution T = 2piab /h

Where a = L/(1-e^2) b = L/root(1-e^2)

Question 8

What is the area of the ellipse K2

Answer 8

Area of ellipse K2 = pi*ab

Question 9

What does K3 imply about c

Answer 9

K3 implies that c = 4*pi^2 *L/h^2 which is same for all planets