HELLLLO AGAIN. Today, i will be crapping about the appilcations of thermal energy transfer! Please turn to your textbook page 140. XIE XIE :D
Yeah, you must be wondering, what is so good about the applications? Well, i will PROVE YOU WRONG TODAY. Physics is useful and without physics, how can we survive!
Go to your kitchen and take a look at those stuffs around your kitchen. Cooking utensils, table mats, wooden ladles!
Cooking utensils like kettles, boilers and others are made up of stainless steel (METAL!) where heating is definately invovled.
As for wooden ladles, it is very useful for stirring or scooping HOT SOUP and rice!
Lastly, table mats are usually made up of cork, so that all your kitchen utensils can be placed on top of them, without damaging your property.
SEE SO USEFUL RIGHT. Well, the woollen clothes in your closet are used to keep you warm on cold days. So you will not fall sick. AHCHOOOOOOOO :D
HAHA. I TOLD YOU there are many many many useful applications in life. Actually, there are more useful stuffs around. Almost everything you see requires physics. Physics is ALMIGHTY AND POWDERFUl. Correction, powerful :D
Once again, i sound like a crazy toothead. Nevermind about me. ANYWAY, BYE! go play with your physical stuffs :D
Now i'll be going through the three processes i've mentioned earlier. CONDUCTION, CONVECTION and RADIATION!
Let's start with CONDUCTION! please turn to your textbook page 130!
What exactly is conduction? Conduction is when heat flows through a material. Therefore, the defination of conduction is when the process of thermal energy transfer without any flow of material medium!
Well how does conduction work? Well metals are the best conductors of heat, so let's use metals as the examples!
Metals are made up of atoms that are very closely packed together. Metals and non-metals are different as metals contain freeee electrons what will move randomly about in the atoms or molecules unlike non-metals. awww, please don't cry mr non-metals :D and yay! metals have more freedom!
So yeah, as you heat a metal, they will vibrate alot alot since they are very closely packed. As they vibrate more, they will BANG into the atoms next to them, and then they will vibrate more again!
Then they bang again, bang bang bang into their neighbours. Metals are so inconsiderate HAH! Yeah and eventually, all these particles will be hotter than before and they will vibrate faster and faster :D
HAHAH, and then in liquids and gases, the particles are not in fixed position so this effect will NOT NOT NOT happen. That makes them UNCOOL, TEEHEE! :D
LIKE THIS!
YAY, done with conduction. Now it's time for convection. Okay, this is sooo confusing :(
So what is convection? Well, it is the transfer of thermal energy in liquids or gases but NOT in solids!
Yes gases and liquid are POOR conductors of energy and heat, and convection will work if we use this two states of matter. It will never ever ever work in solids. BUT WHY WHY WHY? Let Miss Yap do the explanation!
Okay convection only involves the movement of gasses and liquids which carry thermal energy in them.
For solids, the thermal enrgy is transferred through vibrations. When they bang into their neighbours and everybody gets upset and so they bang more and more. Convection doesn't like inconsiderate people like them :D
One example of convection is when you heat water at the bottom of the flask. It will EXPAND and grow fatter. OH NO! The expanded water will be less dense than the surrounding water and water will rise! COOOOOL YEAH!
NOW for the last process, RADIATION. oh i know you're bored, PLEASE DON'T SLEEP :D
So what is radiation? HAH, it the is energy transmitted in the form of electromagnetic waves AND high speed particles. and they DO NOT require a medium for energy transfer!
WAIT. PAUSE AND STARE. radiation has a family! does it sound familiar to you? IT IS THE ELECTROMAGNETIC WAVES!
Infrared radiation is absorbed and emitted by all objects and surfaces. Absorbtion of radiant heat will cause temperature to rise while emission causes temperature of the objects to decrease. So WHAT will affect the rate of infrared radiation?
WELL WELL WELL,
1. COLOURS AND TEXTURE OF SURFACES Well, black surfaces are better absorbers of infrared radiation than shiny shite surfaces. This website http://www.newton.dep.anl.gov/askasci/phy00/phy00156.htm will explain the reason why black is a better absorber!
2. SURFACE TEMPERATURE The higher the temperature of the surface, the higher the rate of infrared radiation!
3. SURFACE AREA The larger the area of the object, infrared radiation will occur at a higher rate.
HELLO AGAIN. nicole was just being some ignorant lame kido. ANYWAY. you know what? I GAVE UP ON THE LINKS ALREADY. it has been a thousand million years since i've blogged, and now i totally forgot everything about blogging! sooooo annnnoying you know :(
So now let's begin with my pro teaching. TEEHEEHEE.
NOW CLASS, TURN TO PAGE 129!
Okay, i shall explain very very very very slowwwwly :D
Now, thermal energy can only be transferred only when there is a difference in temperature! When you feel something hot or cold, that is a temperature difference!
AHHA, i'm pretty sure everyone knows how to differentiate between cold and hot yeah?
So, since you all know that thermal energy exist when there is a difference in temperature, therefore thermal energy will always flow from a region of higher temperature to a region of lower temperature!
So how is thermal energy being transferred then? Well, it is basically transferred by any of these three processes, which are CONDUCTION, CONVECTION and RADIATION!
So how does this three processes occur? Well stay tune for the next episode of MISS YAP'S teaching :D BYEBYE!
okay you know what? i realise the blog was oh-so-boring yeah. like OBVIOUSLY. NO PICTURES BLAH BLAH NOW I SHALL POST PHYSICAL PEEEEEKCHAS! teeeheeee :D
YAY, see huh. gas are far apart, not together and has many spaces in between! liquids yeah, are not uniform, unlike solids. they have a little space in between :D as for solids, they are very closely packed together hence occupying minimum spaces.
hahah, this adds colours to my blog! PUURFECT examples. clap clap for me.
NOW FOR A VERY INSPIRATIONAL VIDEO. DRUMROLL PLEASEEEE :D
that's it. i hope it is more interesting that way. TOOTLES :D
GOOD MORNING CLASS. TODAY MISS YAP IS GOING TO TEACH YOU ABOUT THERMAL PHYSICS TURN TO TEXTBOOK PAGE 121! YES! so let's begin with the properties!
Let me question you! WHAT ARE THE PROPERTIES OF SOLIDS?!
*smart student raises hands and says* WO ZHI DAO! Solid are hard and rigid, which requires a large force to change it's shape. They are incompressible, has high density, has a fixed shape and volume. Cool huh!
BU CUO BU CUO! next question! WHAT ARE THE PROPERTIES OF LIQUIDS?!
*nerdy kids raises hands and says* errrr liquid are incompressible, has a fixed vloume and has high density. Unlike solids, it does not have a fixed shape.
Hmm, good! last question! WHAT ARE THE PROPERTIES OF GASES?!
*bimbo students stands up and say* Aiyoh, cher! This question so easy! Gas ah, are very different from liquid and solid. It is easily compressible, that has low density with no fixed shape or volume. They are compressible as we can't even touch, see or feel them. See i so smart!
HAHA wow, smart teacher produces smart students! okay, i was talking to myself just now, how lame. WELL WELL,These are the properties that we have learnt before. Now, let me explain the above stuffs in detail!
solids :D
So why do solids have high densities? Well apparently, the particles of a solid is closely packed together in a regular pattern that occupies minimum space, resulting in high densities.
Solids have fixed volume and shapes. Have you ever wondered why? Actually, particles vibrate about in fixed positions only. It is held in position by very STRONG intermolecular bonds. This explains the reason why solids have fixed volume and shapes.
liquids :D
Liquids also have high densities. They are randomly arranged with the particles slightly further apart as compared to solids.
Liquids have fixed volumes, but they do not have fixed shape. Why is it so? Well, liquids are free to move about but are confined within the vessel that contains it. It also have attractive forces between the particles. That explains the question :D
Gases :D
Gases has low densities. That is because they are very very far apart. Particles are randomly arranged and will occupy any available spaces
Gases are also easily compressible. They have no fixed volume and shape because the particles have very little attraction between them and it will move about randomly at very high speeds!
Brownian motion! Yes yes, it is a motion of smoke particles. At a higher temperature, smoke particles will be more vigorous, because air molecules are bombarding the smoke particles more frequently. This means that air molecules have greater speeds at higher temperatures. When temperature increases, thermal energy will be converted to kinetic energy, hence causing molecules to move faster!
To conclude the chapter, I have found useful notes on this chapter! if you want, you can try and do it yeah?
