AMC 8 2023 Problem 3

AMC8 2023 年第 3 题

表达式与运算★☆☆☆☆

Wind chill is a measure of how cold people feel when exposed to wind outside. A good estimate for wind chill can be found using this calculation:

(\text{wind chill}) = (\text{air temperature}) - 0.7 \times (\text{wind speed})

where temperature is measured in degrees Fahrenheit (

^{\circ}\mathrm{F}

) and wind speed is measured in miles per hour (mph). Suppose the air temperature is

36^{\circ}\mathrm{F}

and the wind speed is 18 mph. Which of the following is closest to the approximate wind chill?

风寒指数衡量人们在室外受风时感受到的寒冷程度。可用下面的关系式较好地估算风寒指数：

\text{(风寒指数)} = \text{(气温)} - 0.7 \times \text{(风速)}

其中气温以华氏度（

^{\circ}\mathrm{F}

）计量，风速以英里每小时（mph）计量。设气温为

36^{\circ}\mathrm{F}

，风速为 18 mph。下列哪一项最接近此时的风寒指数？

正确答案 · Correct Answer

解析 · Solution

Solution 1

By substitution, we have $$$$

\begin{aligned} (\text{wind chill}) &= 36 - 0.7×18 \\ &= 36 - 12.6 \\ &= 23.4 \\ &\approx 23. \end{aligned}

$$$$

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