(a)V=5.17×1014s−1,ˉV=1.72×106m−1(b)V=4.17×1014s−1,ˉV=2.72×106m−1(c)V=3.17×1014s−1,ˉV=1.72×106m−1(d)V=5.17×1014s−1,ˉV=2.72x106m−1