1：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double degreeCelsius = input.nextDouble();
		double fahrenheit = degreeCelsius*9.0/5.0 + 32;
		System.out.print(fahrenheit);
	}
}

2：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double radius = input.nextDouble();
		double height = input.nextDouble();
		double S = Math.PI*radius*radius;
		double volume = S*height;
		System.out.print("area:" + S + " " + "volume:" + volume);
	}
}

3：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double foot = input.nextDouble();
		double meter = foot * 0.305;
		System.out.println(meter);
	}
}


4：

和第三題差不多

5：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double expenditure = input.nextDouble();
		double reward = expenditure * 0.15;
		double totalMoney = expenditure + reward;
		System.out.println(totalMoney);
	}
}

6：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		System.out.println("Enter a number between 0 and 1000:");
		int num = input.nextInt();
		int sum = 0;
		while(num > 0){
			sum += num%10;
			num /= 10;
		}
		System.out.println(sum);
	}
}


7：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		System.out.println("Enter the number of minutes:");
		int minutes = input.nextInt();
		int days = minutes / (24*60);
		int year = days / 365;
		int day = days % 365;
		System.out.println(year + " years and " + day + " days");
	}
}

8：
//地理不好，說不定就做錯了
import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		int move = input.nextInt();
		long totalMilliseconds = System.currentTimeMillis();
		long totalSeconds = totalMilliseconds / 1000;
		long currentSecond = totalSeconds % 60;
		long totalMinutes = totalSeconds / 60;
		long currentMinute = totalMinutes % 60;
		long totalHours = totalMinutes / 60;
		long currentHour = totalHours % 24;
		currentHour += move;
		if(currentHour < 0)
			currentHour += 24;
		System.out.println("Current time is " + currentHour + ":" + currentMinute + ":" + currentSecond + "GMT");
	}
}

9：

import java.util.Scanner;
public class Main {
	
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		double v1,v0,t;
		System.out.print("Enter v0,v1,and t:");
		v0 = cin.nextDouble();
	    v1 = cin.nextDouble();
	    t = cin.nextDouble();
	    System.out.print("The average acceleration is ");
	    System.out.printf("%.4f\n",(v1-v0) / t);
	}

}

10：
import java.util.Scanner;
public class Main {
	
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		double k,t1,t2;
		System.out.print("Enter the amount of water in kilograms:");
		k = cin.nextDouble();
		System.out.print("Enter the initial temperature:");
		t1 = cin.nextDouble();
		System.out.print("Enter the final temperature:");
		t2 = cin.nextDouble();
		System.out.print("The energy needed is " + (k*(t2-t1)*4184));
	}

}

11：

第一章11題修改一下就好了

12：

import java.util.Scanner;
public class Main {
	
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		double a,v;
		System.out.print("Enter speed and accelerate:");
		v = cin.nextDouble();
		a = cin.nextDouble();
		System.out.println("The minimum runway length for this airplane is " + (v*v)/(2*a));
	}

}

13：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double annualInterest = 0.05;
		double monthlyInterest = annualInterest / 12;
		double money = 100;
		double sum = 0;
		for(int i = 0; i < 6; ++i){
			sum += 100;
			sum = sum*(1+monthlyInterest);
		}
		System.out.println(sum);
	}
}

14：

import java.util.Scanner;
public class Test{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double pounds = input.nextDouble();
		double inches = input.nextDouble();
		double weight = pounds * 0.45359237;
		double height = inches * 0.0254;
		double BMI = weight / Math.pow(height, 2.0);
		System.out.println("BMI is:" + BMI);
	}
}


15：
import java.util.Scanner;
public class Main {
	
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		double x1,y1,x2,y2;
		System.out.print("Enter x1 and y1:");
		x1 = cin.nextDouble();
		y1 = cin.nextDouble();
		System.out.print("Enter x2 and y2:");
		x2 = cin.nextDouble();
		y2 = cin.nextDouble();
		System.out.println("The distance between the two points is " + Math.sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1)));
	}

}

16：
import java.util.Scanner;
public class Main {
	
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		double side;
		System.out.print("Enter the side:");
		side = cin.nextDouble();
		System.out.println("The area of the hexagon is " + (Math.sqrt(3)*3/2)*side*side);
	}
}

17：

import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double t = input.nextDouble();
		double v = input.nextDouble();
		double rt = 35.74+0.6215*t-35.75*Math.pow(v, 0.16)+0.4275*t*Math.pow(v, 0.16);
		System.out.println(rt);
	}
}

18：

import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		System.out.println("a    b    pow(a,b)");
		for(int i = 1; i <= 5; ++i){
			int a = i;
			int b = i+1;
			int c = (int)Math.pow(a, b);
			System.out.println(a + "    " + b + "    " + c);
		}
	}
}


19：
海倫公式和兩點間距離公式

20：

import java.util.Scanner;
public class Main {
	
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		double balance,interestRate;
		System.out.print("Enter the balance and interest rate(e.g.,3 for 3%):");
		balance = cin.nextDouble();
		interestRate = cin.nextDouble();
		System.out.println("The interest is:" + balance*(interestRate/1200));
	}
}

21：
import java.util.Scanner;
public class Main {
	
	public static void main(String[] args){
		Scanner cin = new Scanner(System.in);
		double investment,interestRate,year;
		System.out.print("Enter investment amount:");
		investment = cin.nextDouble();
		System.out.print("Enter annual interest rate in percentage:");
		interestRate = cin.nextDouble();
		System.out.print("Enter the number of years:");
		year = cin.nextDouble();
		System.out.println("Accumulated value is $" + investment*Math.pow((1+(interestRate/100)/12), year*12));
	}
}
22：

import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		System.out.print("Enter an amount in double , for example 11.56: ");
		double amount = input.nextDouble();
		int remainingAmount = (int)((amount+0.005)*100);
		
		int numberOfOneDollars = remainingAmount / 100;
		remainingAmount = remainingAmount % 100;
		
		int numberOfQuarters = remainingAmount / 25;
		remainingAmount = remainingAmount % 25;
		
		int numberOfDimes = remainingAmount / 10;
		remainingAmount = remainingAmount % 10;
		
		int numberOfNickels = remainingAmount / 5;
		remainingAmount = remainingAmount % 5;
		
		int numberOfPennies = remainingAmount;
		
		System.out.println("Yours amount " + amount + " consists of");
		System.out.println("    " + numberOfOneDollars + " dollars");
		System.out.println("    " + numberOfQuarters + " quarters");
		System.out.println("    " + numberOfDimes + " dimes");
		System.out.println("    " + numberOfNickels + " nickels");
		System.out.println("    " + numberOfPennies + " pennies");
		
	}
}


23：

import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner input = new Scanner(System.in);
		double distance = input.nextDouble();
		double unit = input.nextDouble();
		double price = input.nextDouble();
		double cost = (distance/unit)*price;
		System.out.println(cost);
	}
}