Q. A space station is constructed in the shape of a hollow ring of mass 5.50 x 10^4 kg. Members of the crew walk on a deck formed by the inner surface of outer cylindrical wall of the ring, with radius 115m. At rest when constructed, the ring is set rotating about its axis so that the people inside experience effective free-fall acceleration equal to g. The rotation is achieved by firing two small rockets attached tangentially to opposite points on the rim of ring.
(a) What angular momentum does the space station acquire?
(b) For what time interval must the rockets be fired if each exerts a thrust of 120 N?