1)设小芳顺流所需时间为t1 逆流所用时间为t2
(0.39+0.01)t1=60 t1=150s
(0.39-0.01)t2=60 t2=157.89s
所用时间t=t1+t2=307.89s
2)设出发点据柳树距离为L
怎有 2.5*60=L/(0.585-0.015) +L/(0.585-0.015)
150=L/0.6+L/0.57 L=43.86
3)t=l/(x+n) +l/(x-n)
整理等:l=(x²-n²)t / 2x
望采纳!祝学习进步!
1)设小芳顺流所需时间为t1 逆流所用时间为t2
(0.39+0.01)t1=60 t1=150s
(0.39-0.01)t2=60 t2=157.89s
所用时间t=t1+t2=307.89s
2)设出发点据柳树距离为L
怎有 2.5*60=L/(0.585-0.015) +L/(0.585-0.015)
150=L/0.6+L/0.57 L=43.86
3)t=l/(x+n) +l/(x-n)
整理等:l=(x²-n²)t / 2x
望采纳!祝学习进步!