建议使用官方纸质指南,查看对照完整题目
【OG20-P277-287题】
A certain truck uses112 +kv2 gallons of fuel per mile when its speed is v miles per hour, where k is a constant. At what speed should the truck travel so that it uses 512 gallon of fuel per mile?
(1) The value of k is 110800 .
(2) When the truck travels at 30 miles per hour, it uses 16 gallon of fuel per mile.
-
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx



题干:求1/12+kv^2=5/12时v的值,k是常数,能把k的值求出来即可
条件1:k=1/10800,充分
条件2:1/12+k*30^2=1/6,可以求出k的值,充分
题目讨论 (2条评论)

-
贾思敏
害,应是没把30看成v带进去算
0
0 回复 2021-09-13 13:54:44
-
EMEI
v不能取负数
0
0 回复 2019-08-06 08:55:27