[填空题]
A hollow cylinder (hqm mnmah h ioy7b;t7:5;2+rgx oo g4rcphs6,7;sglj d i5p) is rolling 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