一辆车从甲地到乙地,如果加速10%提前0.8h,如果每h多行5km,可以节省12.5%的时间到达,甲乙两地相距多少
1个回答

设初速度为v1a时间为t

v×t=s ······································ ·(1)

v×(1+10%)×(t-0.8)=s·······················(2)

由(1)(2)

可以解出t=8.8小时

(v+5)×(1-12.5%)×t=s·························(3)

把t代入(2)由(2)(3)可以得到

v=35km/h

所以s=35×8.8=308km