You know that moment when your bare foot hits a cold floor? Kind of terrible, right? So why is a tile floor so cold, while a carpeted one is warmer, and easier for your bare foot to deal with? And similarly, why is a breeze cool while sunshine feels warm? The answer is thermal energy, and more precisely, the ways in which thermal energy moves from one place to another.
Another word for thermal energy, by the way, is heat. "Thermal energy," "heat energy" and "heat" all mean pretty much the same thing. Watch this video to learn what makes different objects hot or cold and what thermal energy has to do with it. Then, answer the question under Take Notes, below. You may read the transcript to the video, and watch it as many times as you like.
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Thermal energy is all around us. We see its effect everyday (ice melting, thermometer rising, popcorn kernel popping). And we feel it too.
Thermal energy - also known as heat energy-- is all about the movement of molecules. When molecules are moving fast they have a lot of energy and we sense it as heat. When they are moving very little they have less energy and we sense it as cold. And temperature is just a measure of that movement-- literally the measure of how fast molecules are moving.
But it’s the transfer of that energy that allows us to feel things like hot and cold. Energy is always trying to find equilibrium- a balanced state- so thermal energy will spread through the collisions of molecules from higher energy (warmer) materials to lower energy (cooler energy). That is why hot things cool down (steaming mug), and cold things heat up (ice melting).
Thermal energy can travel within and between the different phases of matter -- solid, liquid, gas and even vacuums. It can get pretty complicated, but there are three main ways energy transfers: conduction, convection & radiation.
So if it’s too hot to handle, just transfer some thermal energy until it’s too cold to hold.
In this lesson you will learn some basic information about thermal energy and the different ways it can move from one object to another. You’ll watch a short introduction to thermal, or heat, energy, and then three animations that explain the three different ways heat is transferred. After taking notes and online quizzes, you’ll have a chance to review and organize what you’ve learned. Then you will produce your own project in which you’ll summarize all you have learned.
1) What is thermal energy?
2) How are cold objects different from hot objects?
3) What are the three main ways thermal energy transfers?
Note your answers in the box below. Click SAVE when you have finished. To see your saved or submitted work again, click MY WORK at the top of the page.