Physics (very long question)
posted by Anonymous .
Two astronauts (Fig. P8.68), each having a mass of 84.0 kg, are connected by a 10.0 m rope of negligible mass. They are isolated in space, moving in circles around the point halfway betwen them at a speed of 5.80 m/s. Treating the astronauts as particles, calculate each of the following.
(a) the magnitude of the angular momentum of the system
kg·m2/s
(b) the rotational energy of the system
kJ
By pulling on the rope, the astronauts shorten the distance between them to 5.00 m.
(c) What is the new angular momentum of the system?
kg·m2/s
(d) What are their new speeds?
m/s
(e) What is the new rotational energy of the system?
kJ
(f) How much work is done by the astronauts in shortening the rope?
kJ
(Could someone tell me how to do each part?)

I will be happy to critique your work. Most of this is very straightforward.