初始狀態(tài)與最終狀態(tài)下通訊員都在隊(duì)尾,所以通訊員對(duì)地位移60m.
設(shè)通訊員跑到隊(duì)首所用時(shí)間為t1,則
t1*V人=80+t1*v隊(duì),t1=80/(V人-v隊(duì))
此時(shí)所跑路徑為t1*V人=80*V人/(V人-v隊(duì))
然后通訊員又跑到隊(duì)尾,所跑路程為
80*V人/(V人-v隊(duì))-60
跑回隊(duì)尾所用時(shí)間為
t2=(80*V人/(V人-v隊(duì))-60)/V人
而整個(gè)過程所用時(shí)間為
t=60/v隊(duì)
因t=t1+t2
所以
80/(V人-v隊(duì))+(80*V人/(V人-v隊(duì))-60)/V人=60/v隊(duì)
化簡得
(v隊(duì)/V人)/(1-v隊(duì)/V人)^2=60/80
設(shè)v隊(duì)/V人=p,則
p/(1-p)^2=3/4
解得p=1/3
所以,v隊(duì) :V人= 1:3
通訊員跑動(dòng)路程為：
80*V人/(V人-v隊(duì))+80*V人/(V人-v隊(duì))-60
=2*80/(1-p)-60=180m
通訊員往返時(shí)間比為:
80*V人/(V人-v隊(duì)) :(80*V人/(V人-v隊(duì))-60) =
80/(1-p) :(80/(1-p)-60)= 2 :1
此過程通訊員對(duì)地位移為___60_______m,通訊員跑動(dòng)的路程是_____180_____m,（V隊(duì)）：（V人）=__1：3______,通訊員往返的時(shí)間比為_____2：1___________.