Question

1.小明和小亮分别以20km/h和30km/h的速度骑车,若他们分别从相距100km的甲、乙两镇相向出发,相遇时最少经过

Answer 1

1.s=100km,v1=20km/h,v2=30km/h

--->t=s/(v1+v2)=100/(20+30)=100/50=2(h)

2.s=6km,v1=10km/h,v2=12km/h

--->t=s/(v2-v1)=6/(12-10)=6/2=3(h)