Exercise03_20.java

package ch_03;

import java.util.*;

/**
 * *3.20 (Science: wind-chill temperature) Programming Exercise 2.17 gives a
 * formula to compute the wind-chill temperature. The formula is valid for
 * temperatures in the range between −58ºF and 41ºF and wind speed greater than
 * or equal to 2.
 * <p>
 * Write a program that prompts the user to enter a temperature and a wind
 * speed. The program displays the wind-chill temperature if the input is valid;
 * otherwise, it displays a message indicating whether the temperature and/or
 * wind speed is invalid.
 */
public class Exercise03_20 extends Exercise03_21 {
    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);
        System.out.println("Enter the temperature in Fahrenheit between -58°F and 41°F: ");
        double temp = input.nextDouble();

        System.out.println("Enter the wind speed (>=2) in miles per hour: ");
        int windSpeed = input.nextInt();

        if (temp >= -58 && temp <= 41 && windSpeed >= 2) {

            double vToPow16 = Math.pow(windSpeed, 0.16);

            double twc = 35.74 + 0.6215 * temp - 35.75 * vToPow16 + 0.4275 * temp * vToPow16;
            System.out.println("The wind chill index is " + twc);
        } else {
            System.out.println("Please check to make sure you are entering valid input.");
        }
        input.close();
    }
}