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
I would use miles
Because miles will give you less of an answer
Answer:
stars share a gravitational force with the galaxy while nearby galaxies do not share a gravitational field.
Explanation:
stars will not collide because they are bound by a gravitational orbit around the galaxy
Answer:True
Explanation:
Albedo is a unit-less, non-dimensional quantity that shows how well a surface reflects solar energy. The value of albedo can vary from 0 to 1, 0 being the black and 1 refers to a white surface. Zero means Surface is a perfect absorber i.e. it absorbs all the incoming rays incidents on it. Albedo 1 means the surface is a perfect reflector.
Albedo usually applies for visible light, even though it may involve some of the infrared regions of the electromagnetic spectrum. The average albedo associated with earth surface is 30%
Both objects have the same electrical charge. Opposite charges attract. And if they were neutral they would not do anything.