Ch.5.3 Flashcards
The energy ________________ from a ________________ object to a ________________ one is called heat.
transferred, hotter, colder
Three methods of heat transfer:
1.
2.
3.
Conduction
Convection
Radiation
Conduction requires a ________________ (such as a ________________, a ______________ or a ______________) to transfer heat.
medium, solid, liquid, gas
-
an object
between two objects in contact
heat can be transferred by conduction through an object from the __________ end to the _________ end. Heat can be conducted in __________ _________________.
hot, cold
any direction
some materials conduct heat ______________ ____________ ______________.
faster than others
________________ such as ________________ and ________________ conduct heat ________________.
They are ________________ ________________ of heat.
Metals, copper, iron, fast, good conductors
In general, _____________-________________ conduct heat more ________________. They are ________________ ________________/ ________________ of heat.
Non-metals, slowly, poor conductors, insulators
Please list out 7 items in the order of poor conductor of heat->good conductor of heat. 1. 2. 3. 4. 5. 6. 7.
Plastic Wood Glass Stainless steel Iron Aluminium Copper
In general, liquids are ________________ ________________ of heat.
poor conductors
________________ and _____________ are poor conductors of heat.
Water, air
Uses of good conductors of heat:
- some ________________ ________________ are made of good conductors of heat such as ____________ and ________________
- these materials transfer heat very ______________ to the ___________
- this ________________ cooking time
- a ________________ ________________ is one of the components inside a ________________
- it is made of metal which can ________________ _____________ ____________ to _____________ the computer from _________________
Cooking utensils, iron, copper, quickly, food, reduces, heat sink, computer, conduct heat away, prevent, overheating
Uses of poor conductors of heat:
- most of the ________________ of ________________ ________________ are made of poor conductors of heat
- ____________ and ________________ can ________________ a lot of ________________ inside them
- since air is a poor conductors of heat, we can wear _________ or _____________ ________________ to keep warm
- similarly, animals like ________________ ________________ keep warm by ________________ __________ in their ___________
Handles, cooking utensils, fur, feathers, trap, heat, fur, down clothings, polar bears, trapping air, fur
In a ______________ ______________, hot water ______________ and cold water in the tube ______________ to take the place of the ______________ ______________ ______________. This cycle carries ______________ from ______________ ______________ to ______________ through _________________.
convection current, rises, sinks, risen hot water
heat, one place, another, convection
Convection in ______________ takes place in the ______________ ______________ as in liquids. When the air above the candle flame gets ______________, it ______________. The ______________ air from the __________________ ______________ to take the place of the ______________ air. The ______________ of air forms a ______________ ______________ of air.
gases, same way, hot, rises, cold, surroundings, sinks, hot, movement, convection current
Similar to conduction, convection requires a _____________ to transfer heat.
However, convection can take place only in _________________ and _________. It cannot take place in _____________.
medium, liquids, gases, solids
Some electrical appliances make use of convection:
- the _____________ _____________ of an electric kettle is placed at the _____________ so that heat can be transferred by a _____________ _____________.
- an air conditioner is usually _____________ near the _____________. __________ air is blown out and _____________ while ________ air _____________ to _____________ it. A _____________ _____________ is formed and the room is _____________.
heating element, bottom, convection current
installed, ceiling, cold, sinks, hot, rises, replace, convection current, cooled
We can observe many _______________ showing convection of heat in ________________: _____________ _____________ and _____________ _____________ are the effects of convection currents.
phenomena, Nature, sea breezes, land breezes
Sea breezes: during the day, land _____________ heat from the Sun _____________ than sea water and the land becomes ________________________________________. Hot air _____________ from land and cold air _____________ in from the sea to replace the ______________________________________.
Absorbs, faster, hotter than the sea, rises, blows, hot air that has risen
Land breezes: at night, the land _____________ _____________ faster than the sea and the land becomes _____________. Hot air rises from the _____________ and cool air blows from _____________ to _____________.
Cools down, colder, sea, land, sea
The space between the ____________ and the _________________ is a _________________. Heat cannot be transferred through a vacuum by _________________ or _________________. This is because both processes require a _________________ to _________________ ____________.
Sun, Earth, vacuum, conduction, convection, medium, transfer heat
Heat is transferred from the Sun to the Earth by _________________. Another example in real life is when we sit near an _________________ _________________, heat is transferred to us mostly by _________________.
Radiation, electric heater, radiation
All objects _________________ radiation. For example, when we stand under the Sun, our bodies _________________ _________________ from it and our body temperature will _________________.
absorb, absorb radiation, increase
In general, _________________ ________________ _________________ are _________________ absorbers of radiation, while _________________ _________________ _________________ are _________________ absorbers of radiation.
dull black surfaces, good, shiny silver surfaces, poor
