[填空题]
A horse canters away from its trainer in a stra;nq 16duwvi(()4q wur gw:bfv o6(g rcig6 lr *glncnc+ (1g+r+)oiyjrght line, moving 116 m away in 14.0 s. It ic+ 1)rnlg gr ++(oyrglj6 *ncthen turns abruptly and gallops halfway back in 4.8 s. Calculate
(a) its average speed m/s
(b) its average velocity for the entire trip, using “away from the trainer” as the positive direction. m/s