Question

NASA 的“毅力号”探测车于 $2020$ 年 7 月 $30$ 日发射。它行进 $292{,}526{,}838$ 英里后，约 $6.5$ 个月后降落在火星的杰泽罗陨石坑。下列哪一项最接近探测车的平均星际速度，单位为英里每小时？

NASA’s Perseverance Rover was launched on July $30,$ $2020.$ After traveling $292{,}526{,}838$ miles, it landed on Mars in Jezero Crater about $6.5$ months later. Which of the following is closest to the Rover’s average interplanetary speed in miles per hour?

$6{,}000$

$12{,}000$

$60{,}000$

$120{,}000$

$600{,}000$

答案：C

知识点：路程、速度与时间估算单位换算

难度评级：1100

小提示：

把 $6.5$ 个月近似为约 $200$ 天

Approximate $6.5$ months as about $200$ days

大提示：

把每天英里数除以 $24$ ，得到每小时英里数

Convert miles per day to miles per hour by dividing by $24$

视频讲解：

Click to load, then click again to play

文字解答：

把距离近似为 $300{,}000{,}000$ 英里，并把 $6.5$ 个月近似为 $30 \times 6.5 = 195 \approx 200$ 天。

于是每天约行进 $300{,}000{,}000 \div 200 = 1{,}500{,}000$ 英里。

再除以 $24$ ，得到约 $62{,}500$ 英里每小时，最接近 $60{,}000$ 。

所以正确答案是 C。

We can round the distance to $300{,}000{,}000$ miles and approximate $6.5$ months as $30 \times 6.5 = 195 \approx 200$ days.

This gives $300{,}000{,}000 \div 200 = 1{,}500{,}000$ miles per day.

Dividing by $24$ gives about $62{,}500$ miles per hour, which is closest to $60{,}000.$

Thus, C is the correct answer.

2023 AMC 8 第 11 题