[填空题]
A hollow cylinder (hoop) i 0* uaa9s9p:qhbvsx.n5lj 6cu s 6ygc60 r-owrurolling on a horizontal surface at speed 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