[填空题]
A hollow cylinder (hoop) is rolling on a horizontal surfac i nv87sfx8w6ge at speed v=u2a5iqw;;rcf6; hh zp 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