Heat Energy Transfer Conduction Convention Radiation Essential Standard

Heat Energy Transfer Conduction, Convention & Radiation

Essential Standard • 6. P. 3 Understand characteristics of energy transfer and interactions of matter and energy.

Clarifying Objective • 6. P. 3. 1 Illustrate the transfer of heat energy from warmer objects to cooler ones using examples of conduction, radiation and convection and the effects that may result.

Essential Questions • What are the different ways that energy be transferred?

Heat Transfers • Heat atoms are always looking to try to find cold atoms • Heat atoms can give cold atoms their heat 3 different ways • These 3 ways are called ① Conduction ② Convection ③ Radiation

Why Does Heat Transfer • Heat transfers from object to object because EVERY OBJECT IS TRYING TO BECOME WARMER • Objects try to become what the dominate temperature is (room)

Conduction • Conduction is the first way atoms with heat in them will transfer them to cold atoms • Conduction is the heat transfer of two solids joined together through a conductor (direct contact)

Conduction • A conductor is what actually transfers the heat from one solid to another solid • Conduction mediums are always solids (they only transfer heat through solids)

Conductor • Conductors are mediums that will transfer heat from one solid to another • Hot atoms move through the conductors to transfer their heat to cold atoms • Some items are better conductors than others

Conductor • Solids are always the best conductors because their atoms are attached and not spread out so the heat can move through them better • Gases are the worst conductors because their atoms are so spread out and it will take longer for them to bump into each other • Metals are the best conductors because they are solids and their atoms have the most density

How Does Conduction Happen? ① Solid with hot atoms look for cold solid atoms ② The conductor is placed between the solid hot atoms & the solid cold atoms ③ Hot atoms (excited) vibrate & hit each other & move through the conductor

How Does Conduction Happen? ④ Once the hot atoms have moved through the conductor they contact the cold atoms of the other solid ⑤ They transfer the heat from their atoms (hot atoms) to the cold atoms and warm them up ⑥ Now all atoms in both solids are warm

Conduction (Example) • http: //www. youtube. com/watch? v=Gyj 444 FK 0 zs

Convection • Convection is the moving of heat through gas or liquid mediums • Convection will only transfer heat through gasses or liquids

Convection Process • http: //www. youtube. com/watch? v=li. Kc. JKjv. Fc Y • 0: 00 -1: 36

How Does Convection Happen? ① Hot atoms form and become excited and start to vibrate ② As they vibrate the hot atoms rise because the atoms begin to separate and become less dense ③ The hot atoms that rise push the cold atoms to the bottom and they are heated

How Does Convection Happen? ④ Then those atoms rise and push the next batch of cold dense atoms to the bottom to be warmed again ⑤ The process continues and forms a CONVECTION CURRENT

VIDEOS • https: //www. youtube. com/watch ? v=N 8 m. Cn 8 f 3 za 0 • https: //www. youtube. com/watch ? v=B 8 H 06 ZA 2 xmo • https: //www. youtube. com/watch ? v=li. Kc. JKjv. Fc. Y&t=6 s

Convection Example • http: //www. youtube. com/watch? v=Gyj 444 FK 0 zs

Radiation • Transfer of heat atoms through electromagnetic wave motion • Radiation involves light photons not atom particles • All waves on the Electromagnetic Spectrum will transfer heat through radiation ① ② ③ ④ ⑤ ⑥ Radio Waves Microwaves Infrared Waves Ultraviolet Waves X-Ray Waves Gamma Waves

Electromagnetic Spectrum

Radiation (Heat Absorption) • About 50% (half) of the radiation heat transfer comes from VISIBLE LIGHT part of the spectrum • The amount of heat absorbed through radiation depends on… ① Intensity of the waves (visible waves are most intense) ② Color of the object the radiation wave is hitting • This is why darker colors absorb more heat than lighter colors

How Does Radiation Happen? ① Waves from the Electromagnetic Spectrum radiate heat ② The electromagnetic waves carry the heat through any medium ③ The heat waves hit the object and warm it up

Radiation Example • Campfires radiate heat through light waves from the electromagnetic spectrum • Microwaves do the same thing

Radiation Video • https: //www. youtube. com/watch? v=Zw 0 p. HT 47 AAU

Essential Questions • Get with a partner and answer… • What are the different ways that energy be transferred?

Important Points • Heat transfer occurs because all objects are trying to become warmer • Convection is heat transfer through currents • Conduction is heat transferring through direct contact between objects • Convections currents occur in liquids & gasses only • Radiation is the transfer of heat through photons on waves • It does not include atoms • Radiation depends on how INTENSE the wave is & the COLOR of the object it is warming • • • Conduction must have conductors to occur Metals are good conductors because their atoms are close together Conduction only occurs through two SOLIDS