Transfer Of Thermal Energy
Übersicht
A metal spoon in a hot drink soon burns your fingers, yet a wooden spoon stays cool. Warm air rises from a radiator to heat a whole room, and the Sun's warmth crosses the empty vacuum of space to reach us. These are the three ways thermal energy moves: conduction, convection and radiation.
In this topic you will describe experiments that reveal good and bad conductors, explain convection in terms of density changes, and learn how surface colour and texture affect infrared radiation. You will also see why an object stays at a steady temperature only when energy in balances energy out, and how that same balance controls the temperature of the Earth.
Ziele
- Describe experiments to demonstrate the properties of good thermal conductors and bad thermal conductors (thermal insulators)
- Know that convection is an important method of thermal energy transfer in liquids and gases
- Explain convection in liquids and gases in terms of density changes and describe experiments to illustrate convection
- Know that thermal radiation is infrared radiation and that all objects emit this radiation
- Know that thermal energy transfer by thermal radiation does not require a medium
- Describe the effect of surface colour (black or white) and texture (dull or shiny) on the emission, absorption and reflection of infrared radiation
- [Supplement] Describe thermal conduction in all solids in terms of atomic or molecular lattice vibrations and also in terms of the movement of free (delocalised) electrons in metallic conductors
- [Supplement] Describe, in terms of particles, why thermal conduction is bad in gases and most liquids
- [Supplement] Know that there are many solids that conduct thermal energy better than thermal insulators but do so less well than good thermal conductors
- [Supplement] Know that for an object to be at a constant temperature it needs to transfer energy away from the object at the same rate that it receives energy
- [Supplement] Know what happens to an object if the rate at which it receives energy is less or more than the rate at which it transfers energy away from the object
- [Supplement] Know how the temperature of the Earth is affected by factors controlling the balance between incoming radiation and radiation emitted from the Earth’s surface
Audiolektion
Diese Lektion in der App anhoren
Mindmap
Dieses Thema ist als Karte dargestellt, damit die Zusammenhange sichtbar werden.
Mindmap in der App offnen
Lernkarten
Schnelles Abfragen der Fakten, die zu diesem Thema gepruft werden.
Diese Karten in der App uben
Lektionshinweis
Vollstaendige Lernnotiz in der Green Bridge App
Holen Sie sich die Green Bridge CBT App auf Handy oder Computer fuer die komplette IGCSE-Bibliothek: fruehere Pruefungen, Bewertungsschemata, Mindmaps, Lernkarten und Audiolektionen.
Unterrichtsbewertung
Herzlichen Glückwunsch zum Abschluss der Lektion über Transfer Of Thermal Energy. Jetzt, da Sie die wichtigsten Konzepte und Ideen erkundet haben,
Sie werden auf eine Mischung verschiedener Fragetypen stoßen, darunter Multiple-Choice-Fragen, Kurzantwortfragen und Aufsatzfragen. Jede Frage ist sorgfältig ausgearbeitet, um verschiedene Aspekte Ihres Wissens und Ihrer kritischen Denkfähigkeiten zu bewerten.
Nutzen Sie diesen Bewertungsteil als Gelegenheit, Ihr Verständnis des Themas zu festigen und Bereiche zu identifizieren, in denen Sie möglicherweise zusätzlichen Lernbedarf haben.
- Which method of thermal energy transfer can occur through a vacuum? A. conduction B. convection C. radiation D. none of these Answer: C
- Metals are good thermal conductors mainly because they contain: A. large atoms B. free electrons C. trapped air D. water Answer: B
- Warm fluid rises in convection because it becomes: A. denser B. less dense C. heavier D. solid Answer: B
- Which surface is the best emitter of infrared radiation? A. shiny silver B. polished white C. dull black D. shiny white Answer: C
- For an object to stay at a constant temperature, the energy it receives must be: A. greater than energy lost B. equal to energy lost C. less than energy lost D. zero Answer: B
Bearbeiten Sie diese Fragen in der App
Bearbeiten Sie diese Fragen in der App
Empfohlene Bücher
Weiterlernen mit offenen Quellen
-
Lehrbuchabschnitt
Conduction
Your feet feel cold as you walk barefoot across the living room carpet in your cold house and then step onto the kitchen tile floor. This result is intriguing, since the carpet and tile floor are both at the same temperature. The different sensation you feel is explained by the different rates of he
"College Physics: Conduction" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/college-physics/pages/14-5-conduction. Access for free at https://openstax.org/books/college-physics/pages/1-introduction
-
Lehrbuchabschnitt
Radiation
You can feel the heat transfer from a fire and from the Sun. Similarly, you can sometimes tell that the oven is hot without touching its door or looking inside—it may just warm you as you walk by. The space between the Earth and the Sun is largely empty, without any possibility of heat transfer by c
"College Physics: Radiation" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/college-physics/pages/14-7-radiation. Access for free at https://openstax.org/books/college-physics/pages/1-introduction
Von anderen Organisationen unter offenen Lizenzen veröffentlicht und wie gewünscht genannt. Links öffnen deren Websites.
Übungsklausuren üben
Möchten Sie Übungsklausuren zu Transfer Of Thermal Energy üben? Laden Sie die Green Bridge CBT App herunter, um Übungsklausuren und vollständige Prüfungssimulationen zu diesem Thema zu erhalten.
Lade die App im Google Playstore herunter.
Alles, was du brauchst, um in JAMB, WAEC & NECO zu glänzen.
