AMC 8 1990 Problem 23
AMC8 1990 年第 23 题
行程问题★★★☆☆
The graph relates the distance traveled [in miles] to the time elapsed [in hours] on a trip taken by an experimental airplane. During which hour was the average speed of this airplane the largest?
该图显示了一架实验飞机在一次飞行中已行驶距离[英里]与已用时间[小时]的关系。在哪一个小时中该飞机的平均速度最大？
- A. / 第一 (0-1)
- B. / 第二 (1-2)
- C. / 第三 (2-3)
- D. / 第九 (8-9)
- E. / 最后 (11-12)
正确答案 · Correct Answer
B
解析 · Solution
Solution 1
The time when the average speed is greatest is when the slope of the graph is steepest. This is in the second hour .
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