*2.17（科学：风寒温度）外面到底有多冷？单独温度值不足以回答这个问题。风速、相对湿度以及日晒等其他因素在确定室外是否寒冷方面也很重要。2001年，国家气象服务（NWS）利用温度和风速计算新的风寒温度来衡量寒冷程度。 计算公式如下所示：
这里的t是室外的温度，以华氏摄氏度为单位，而v是速度，以每小时英里数为单位。是风寒温度。该公式不适用与风速低于2mph，或温度在-58°F以下或者41°F的情况。
编写程序，提示用户输入在-58°F和41°F之间的度数，以及大于或等于2的风速，然后显示风寒温度。使用Math.pow(a, b) 来计算 。
下面是一个运行示例：
Enter the temperature in Fahrenheit between -58 and 41 : 5.3 Enter the wind speed (>= 2) in miles per hour : 6 The wind chill index is -5.56707
*2.17(Science: wind-chill temperature) How cold is it outside? The temperature alone is not enough to provide the answer. Other factors including wind speed, relative humidity, and sunshine play important roles in determining coldness outside. In 2001, the National Weather Service (NWS) implemented the new wind-chill temperature to measure the coldness using temperature and wind speed. The formula is where t_{a} is the outside temperature measured in degrees Fahrenheit, v is the speed measured in miles per hour, and is the wind-chill temperature. The formula cannot be used for wind speeds below 2 mph or temperatures below -58°F or above 41°F. Write a program that prompts the user to enter a temperature between -58°F and 41°F and a wind speed greater than or equal to 2 then displays the wind-chill temperature. Use Math.pow(a, b) to compute . Here is a sample run: Enter the temperature in Fahrenheit between -58 and 41 : 5.3 Enter the wind speed (>= 2) in miles per hour : 6 The wind chill index is -5.56707
参考代码：
package chapter02; import java.util.Scanner; public class Code_17 { public static void main(String[] args) { double OutDoorTemperature,WindSpeed,WindChillIndex; System.out.print("Enter the temperature in Fahrenheit" + " between -58 and 41 : "); Scanner TemperInput = new Scanner(System.in); OutDoorTemperature = TemperInput.nextDouble(); System.out.print("Enter the wind speed (>= 2) in miles per hour : "); Scanner WindSpeedInput = new Scanner(System.in); WindSpeed = WindSpeedInput.nextDouble(); WindChillIndex = 35.74 + 0.6215 * OutDoorTemperature - 35.75 * Math.pow(WindSpeed,0.16) + 0.4275 * OutDoorTemperature * Math.pow(WindSpeed,0.16); System.out.println("The wind chill index is " + WindChillIndex); WindSpeedInput.close(); } } 结果显示： Enter the temperature in Fahrenheit between -58 and 41 : 5.3 Enter the wind speed (>= 2) in miles per hour : 6 The wind chill index is -5.567068455881625 Process finished with exit code 0