[填空题]
A hollow cylinder (hoop) is rolling on a horizontal a t3exvnq-0l+*qal.7ru/e4 6o yka kjsdaw43surface at spee9 bdx 9jyg2s1ij;jp-jd 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