[填空题]
A hollow cylinder (hoopk9r1s,7nb 1 ct0u;k/lyodcwnk s)o4x ) is rolling on a hd5*uz:+ i ctv5iic zh61ly :ohorizontal 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