(4)=/Z=448/6.54×103=685×108m (5)Ek=(3/2)T =(3/2)×1.38×1023×273 565×102(J) 作业:2.222.232.24235.65 10 (J) −21 =  (4) = v/Z 448/6.54 109 =  = 6.8510−8m (5)  k = (3/ 2)k T (3/2) 1.38 10 273 23 =    − 作业：2.22 2.23 2.24 2.3