[填空题]
A carton is given an initial spe *8(2ll+hx raf lt5jpyed of q .7s6+9aizis itr)o w 3.0 $\mathrm{~m} / \mathrm{s}$ up the 22.0$^{\circ}$ plane shown in Fig. 4-55.
(a) How far up the plane will it go?
(b) How much time elapses before it returns to its starting point? Ignore friction.