[填空题]
A hollow cylinder (hoop) is rolling on a horizontal surface khy5j +e nsv33at speed vm,-a abhf28++92kwuav3njj ydqpyf; =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