x=]dx =」-(-v]u。 dt c W12-(y0-vot)2 -g是416 8-4t dt c =/9-4t2+16t+c t=0x=W9-4t2+16t+c=x。=3 .c=0 x=xW9-4t2+16t 结束目录y v dt 0 t = y v 0 0 + c l 2 ( ) 2 0 t v 0 ( )  9 4 +16 2 t t 8 4t =  dt +c 9 4 +16 2 = t t +c t = 0 x =  dx x = 9 4 +16 2 t t +c = x 0 = 3 . c = 0 . x = 9 4 +16 2 t t 结束 目录