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# heat energy watch

1. I'm revising the energy topic
And I don't understand heat transfer by radiation , convection and conduction at all
It's so confusing and difficult for me
2. (Original post by Wildnatxox)
I'm revising the energy topic
And I don't understand heat transfer by radiation , convection and conduction at all
It's so confusing and difficult for me
You've not really explained what you're confused about... but try this

https://www.bbc.com/education/guides/zttrd2p/revision/1
3. radiation = particles or waves radiate around the room and increase the energy where they spread to
convection= hot heat rises up, where it leaves cool air- cycle repeats as cool air heats up; effect is spreading out of heat to cooler areas
conduction= vibrating particles hit other particles and make them vibrate - therefore increasing temp./energy
4. Heat energy is a type of energy that (let's say in this case) keeps us warm. For us to get warm, we need to get heated up. Apart from our internal homeostasis thing, we can get warm by radiation, conduction and convection.
Conduction, Convection and radiation are types of ways the heat energy moves around (transfers)

Conduction happens by when two surface (objects) come in contact (touch each other). Say you put your hand on the radiator (that is turned on). Your hand will get heated up quicker than if you didn't put your hand on it (and you were far away from a radiator). This happens because, 99% (99% because some energy is lost to surroundings) of the heat energy has conducted (been transferred) to your hand. This is the way the heat energy transferred to your hand (by conduction)

Convection happens by movement of air particles. For this to understand, you must know cold air is denser than hot air and therefore, cold air will be lower height than hot air. Say you are in a room, the floor would have cold air and ceiling would have hot air. This understood, now imagine a radiator. When radiator heats up, it has heat energy. This heat energy is absorbed by cold air particles (which is closer to the floor) and therefore its particles vibrate more, turning into hot particle, hence hot air. This will rise to the top of the ceiling. To balance out the particles at the top, when hot air particles rise up, slightly less hot air particles will be pushed down. This creates "convection current". This is how your room is heated up. This can happen in liquids too, but not in solids

Radiation is when energy is transferred from one place to another. Heat is also known an Infrared Radiation (IR), which is part of the EM (Electromagnetic) Spectrum. All the radiation in the EM Spectrum are waves. This means Infrared Radiation (heat) is a wave. This wave carries the energy required to heat up particles in order for them to get hotter. Say you go outside and lie in the sun (sunbathing). The sun will fall on you (obviously if it was a sunny day). The sun emits all the waves in the EM Spectrum, hence emits Infrared Radiation (Heat). This wave travels through space (where no air particles are present) and reaches earth and goes through our atmosphere eventually heating you up. So technically, radiation, is when heat is carried by waves

You might think, convection and radiation might be the same thing, but Convection requires air particles whereas radiation doesn't require air particles. What's the point? Well, it happens to show that for (heat) energy to be transferred, it doesn't require matter (air particles) to be transferred

Hope you understand

If you don't get this, I'm happy to help again

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