[填空题]
(a) What is the angular momentum of a figur53fno;eq6t lle skater spinning atcb+yu/14c v/rl zwzf - 3.5 $rev/s$ with arms in close to her body, assuming her to be a uniform cylinder with a height of 1.5 m, a radius of 15 cm, and a mass of 55 kg? $kg \cdot m^2$
(b) How much torque is required to slow her to a stop in 5.0 s, assuming she does not move her arms? $m \cdot N$
