AMC 8 2019 Problem 5
AMC8 2019 年第 5 题
行程问题★☆☆☆☆
A tortoise challenges a hare to a race. The hare eagerly agrees and quickly runs ahead, leaving the slow-moving tortoise behind. Confident that he will win, the hare stops to take a nap. Meanwhile, the tortoise walks at a slow steady pace for the entire race. The hare awakes and runs to the finish line, only to find the tortoise already there. Which of the following graphs matches the description of the race, showing the distance traveled by the two animals over time from start to finish?
乌龟向野兔发起挑战赛跑，野兔开心的同意了，然后迅速跑到了前面，把行动迟缓的乌龟甩在了后面，野兔很自信自己会赢，于是停下来打了个盹，同时，乌龟以缓慢但恒定的速度走完了全程。野兔醒了，当它跑到终点时，发现乌龟已经在那里了。下面哪张图和上述对比赛的描述相匹配，并正确的展示了这 2 只动物走过的距离 d 与从开始到结束这段时间 t 的关系？
- A.
- B.
- C.
- D.
- E.
正确答案 · Correct Answer
B
解析 · Solution
Solution 1
First, the tortoise walks at a constant rate, ruling out (D). Second, when the hare is resting, the distance will stay the same, ruling out (E) and (C). Third, the tortoise wins the race, meaning that the non-constant one should go off the graph last, ruling out (A). The answer is the only one left.
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