一队士兵以v1=2m/s的速度在公路上匀速前进,队伍长3200m,通讯员骑摩托车以v2=18m/s的速度从队尾向队首传送

2个回答

  • A:先是到头:t1=s/v=3200/(18-2)=200s

    再是到尾:t2=s/v=3200/(18+2)=160s

    加起来:200s+160s=360s=6min

    B:S2=vs=(10+15)*6s=150m

    t=s/v=150/(15-10)=30s