地震波从汶川传播到武汉的时间t=14h30min50s-14h28min=2min50s=170s；地震波传播的路程，即汶川到武汉的距离S=952km=9.52×105m；地震波传播的速度V= S t = 9.52×105m 170s =5.6×103m/s．故答案为：5.6×103．
