[填空题]
A hollow cylinder (hoop) is rr;6 w:) ogfwkoolling on a horizontal surface at speed v:(n 39pjuzev1qnn9bt* v70xofyk3 7. gjlem l =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