[填空题]
A hollow cylinder (hoop) is 3 apraovi:64fxgr4w -qbu8 vwsb 5e75rolling on a horizontal surface at spee qp n+o ,yzq6 y47gpctn4.ntc)gkg /h6d v=3.3 $m/s$ when it reaches a 15 $^{\circ} $ incline. (a) How far up the incline will it go? $\approx$ m (round to one decimal place) (b) How long will it be on the incline before it arrives back at the bottom? s