Answer:
1000 kgm²/s, 400 J
1000 kgm²/s, 1000 J
600 J
Explanation:
m = Mass of astronauts = 100 kg
d = Diameter
r = Radius = 
v = Velocity of astronauts = 2 m/s
Angular momentum of the system is given by

The angular momentum of the system is 1000 kgm²/s
Rotational energy is given by

The rotational energy of the system is 400 J
There no external toque present so the initial and final angular momentum will be equal to the initial angular momentum 1000 kgm²/s

Energy

The new energy will be 1000 J
Work done will be the change in the kinetic energy

The work done is 600 J
<h2>QUESTION:- </h2>
➜what is kepler's law??

Kepler gave the three laws or theorems of motion of the orbitals bodies

This law state that the celestial bodies revolves around the stars in elliptical orbit and star as a single focus.
Example :- Earth revolves around the Sun as assuming it as single focus
This also shows that earth revolves around the sun in elliptical orbit.

Area covered by the planet is equal in equal duration of time irrespective of the position of the planet.
It also states that Angular momentum is constant
As Angular momentum is constant it means areal velocity is also constant.

where:-
A is the area.
T is the time.
L is the angular momentum.
M is the mass of the body.

square of the time of the revolution is directly proportional to the cube of the distance between the planet and star in Astronomical unit.

where:-
T = time of revolution
a is the distance between the planet and star.

Explanation:
Work cannot be increased by using a machine of some kind.
Decibels I think that's the answer