Humidex
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ProblemHumidex is a measurement that gives people an idea of how hot it feels, as opposed to how hot it actually is. For example, on days with a high temperature and high humidity, people often think it's hotter than it actually is. Write a complete Java program that will ask the user for the dew point and the air temperature. Then use the formulas given to calculate and output the humidex. InputUse Scanner class method nextDouble to prompt the user to input D (dew point) and T (air temperature). Use System.out.println to provide an input prompt. Remember to tell the user to enter values in Celsius. ProcessingThe formula for calculating the humidex is: R = 6.11 * e[5417.7530 * ( (1/273.16) - (1/(273.16 + D)) ) ] H = (0.5555) * (R - 10.0) humidex = T + H Notes
OutputEcho the input and then print the output using System.out.println. Use Math.round() to round all output to one decimal place. |
Humidex | |
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SolutionInputThe problem requires two doubles to be read in from the user. One is the dewpoint (in Celsius) and the other is the air temperature (in Celsius). When asking the user to input the numbers, you should prompt them each time asking them for what piece of information you need. Using the Scanner class, you can read doubles in easily. ScannerThe java.util.Scanner class (added in Java 5) allows simple console and file input. ExampleScanner keyboard = new Scanner(System.in); double number = keyboard.nextDouble(); ProcessingOnce you have your two doubles, you can now start programing to work out the humidex. Math.EWith the formula given to you, it needs the constant e, which can be given with the Math.E() method. Example//The double value that is closer than any other to e, the base of the natural logarithms. Math.E() //returns the value e Math.powOne way to solve the problem is to use Math.pow. Example// pow(x, y) returns the x raised to the yth power. Math.pow(2.0,2.0) //returns 2.0 to the power of 2.0, which is 4.0 For x, it would be the constant e. y will be the part of the formula that x is raised too. Math.expThe other option for solving this is to use Math.exp(). Compared to using Math.Power, you will only need to input one value instead of two. This is because e is already set as the base for the power. x will be the part of the formula that e is raised too. Example//exp(x) returns e raised to the xth power Math.exp( 2 );// returns e squared (or e * e), which is approximately 7.3890 OutputYou will have to round the value from the formula to an appropriate value before you print it out. You will be able to achieve this by using Math.round. Math.roundMath.round is a method that will round a double to the nearest integer. If you want to use this method to round a double to a number with decimal places, you must:
Example//Math.round(x) returns x to the nearest integer x = Math.round (34.4567 * 1000) / 1000.0 // returns the double 34.4567 rounded to THREE decimals Print the HumidexOnce you have the humidex value rounded to the appropriate decimal place, print it out using System.out.println(). | ||
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