A space station is constructed in the shape of a hollow ring of mass 4.95 x104 kilogram. Members of the crew walk on a deck formed by the inner surface of the outer cylindrical wall of the ring, with radius 140 meter. At rest when constructed, the ring is set rotating about its axis therefore that the people inside experience an effective free-fall acceleration equal to g. The rotation is achieved by firing two small rockets attached tangentially to opposite points on the outside of the ring.
(a) Find what angular momentum does space station acquire?
kg•m2/s
(b) Obtain how long must the rockets be fired if each exerts a thrust of125 Newton?
s