kelvin-weather-javascript

Kelvin Weather

Deep in his mountain-side meteorology lab, the mad scientist Kelvin has mastered weather prediction.

Recently, Kelvin began publishing his weather forecasts on his website. However there’s a problem: All of his forecasts describe the temperature in Kelvin.

With our knowledge of JavaScript, let’s convert Kelvin to Celsius, then to Fahrenheit.

For example, 283 K converts to 10 °C which converts to 50 °F.

If you get stuck during this project or would like to see an experienced developer work through it, click “Get Unstuck“ to see a project walkthrough video.

Mark the tasks as complete by checking them off

1.

The forecast today is 293 Kelvin. To start, create a variable named kelvin, and set it equal to 293.

The value saved to kelvin will stay constant. Choose the variable type with this in mind.

2.

Write a comment above that explains this line of code.

3.

Celsius is similar to Kelvin — the only difference is that Celsius is 273 degrees less than Kelvin.

Let’s convert Kelvin to Celsius by subtracting 273 from the kelvin variable. Store the result in another variable, named celsius.

4.

Write a comment above that explains this line of code.

5.

Use this equation to calculate Fahrenheit, then store the answer in a variable named fahrenheit.

Fahrenheit = Celsius * (9/5) + 32

In the next step we will round the number saved to fahrenheit. Choose the variable type that allows you to change its value.

6.

Write a comment above that explains this line of code.

7.

When you convert from Celsius to Fahrenheit, you often get a decimal number.

Use the .floor() method from the built-in Math object to round down the Fahrenheit temperature. Save the result to the fahrenheit variable.

8.

Write a comment above that explains this line of code.

9.

Use console.log and string interpolation to log the temperature in fahrenheit to the console as follows:

The temperature is TEMPERATURE degrees Fahrenheit.

Use string interpolation to replace TEMPERATURE with the value saved to fahrenheit.

10.

Run your program to see your results!

If you want to check your work, open the hint.

11.

By using variables, your program should work for any Kelvin temperature — just change the value of kelvin and run the program again.

What’s 0 Kelvin in Fahrenheit?

12.

Great work! Kelvin can now publish his forecasts in Celsius and Fahrenheit.

If you’d like extra practice, try this:

• Convert celsius to the Newton scale using the equation below

Newton = Celsius * (33/100)

• Round down the Newton temperature using the .floor() method
• Use console.log and string interpolation to log the temperature in newton to the console

Solution

//Temperature in Kelvin
const kelvin = 293;

//Temperature in Celsius (conversion from Kelvin)
let celsius = kelvin - 273;

//Temperature in Farenheit (convert from Celsius)
//used Math.floor() method to round number to whole number
let farenheit = Math.floor(celsius * (9 / 5) + 32);

//Temperature in Newton Scale (convert from Celsius)
//Use Math.floor() method to round number to whole number
let newton = Math.floor(celsius * (33 / 100));

//Answers
console.log(`The temperature is ${kelvin} degrees Kelvin.`);
console.log(`The temperature is ${celsius} degrees Celsius.`);
console.log(`The temperature is ${farenheit} degrees Fahrenheit.`);
console.log(`The temperature is ${newton} degrees Newton.`);

## The temperature is 293 degrees Kelvin.
## The temperature is 20 degrees Celsius.
## The temperature is 68 degrees Fahrenheit.
## The temperature is 6 degrees Newton.