what are the 3 types of heat transer and give a brief desciption of each.
the 3 types of heat transfer are: Conduction, convection and radiation. Conduction is heat transfer through a solid, Convection is heat transfer through either a liquid or a gass. Radiation is heat emmited or absorbed by any object
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Why are metals good conductors?
Metals are mainly good conductors because of their free electrons
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How can heat loss be prevented in your own home?
There are 5 ways to prevent heat loss: 1) loft insulation 2) cavity wall insulation 3) double glazing 4) draught proofing and 5) thick curtains
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Which way does thermal energy normally flow?
from hot to cold
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Why does concrete feel colder than carpet when they’re the same temperature?
The concrete takes the heat away from your hand quicker
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Why is it better to wear lots of thin layers to keep warm than one big warm layer?
Air gets trapped between the layers and fibers of your clothes and dry air is a very good insulator so your heat is kept in.
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What factors effect how much a object emits/absorbs heat?
a. S.A :VOLUME ratio b.Shape c.Temperature difference
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What is the equation to calculate the efficiency of anything?
efficiency= useful energy out put / total energy input
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Cost of Electricity Electricity meter measures units Unit is known as kWh. But how do we calculate the price of electricity?
units=KWs*hrs, Cost=units*price
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what are non-renewable energy sources, give examples and mention some of their dissadvantages
Non renewable energy sources are sources of energy that will run out. 75% of our energy comes from these: coal, oil and natural gasses. these are bad because they produce harmful gasses known as green house gasses which contribute to global warming.
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How are fossil fuels burnt to give us electricity?
1. Fuel is burnt and the heat given off is used to boil water. 2. The steam turns the turbine which turns a magnet in coiled wire. 3. This produce current and voltage . 4. Then converted into electricity. 5. Steam to cooling tower where hot air rises
1. It involves Wind turbines up in exposed areas e.g. on moors of coastal areas. 2. Each wind turbine has its own generator so electricity produces directly from the blades turning 3. No pollution 4. Spoil the view. 1500 to replace 1 coal power satio
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Solar
1.Solar cells create electricity directly from sunlight. Initial expensive. Ideal for appliances not requiring much energy. 2.Remote places 3.No pollution 4.Only in daytime 5.Energy is free and running costs minimal 6.Solar panels are different...
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hydroelectricity
1. Requires flooding a valley and building a dam 2. Water is caught and allowed out through turbines 3. Big impact on environment 4. No problem with reliability 5. No fuel costs
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wave
1. Need lots of small wave convertors around the coast 2. As wave comes to shore they provide an up and down motion which can be used to drive a generator 3. No pollution but spoils view and hazard to boats 4. Unreliable 5. No fuel or running cost.
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tidal
1.Tidal barrages are Big dams built across a river. 2.As the tide comes in the water builds up and it let out through turbines. 3.Source – Sun moon and gravity 4.No pollution but problems with boats and wildlife. 5.Tides are reliable but the he
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Other cards in this set
Card 2
Front
Why are metals good conductors?
Back
Metals are mainly good conductors because of their free electrons
Card 3
Front
How can heat loss be prevented in your own home?
Back
Card 4
Front
Which way does thermal energy normally flow?
Back
Card 5
Front
Why does concrete feel colder than carpet when they’re the same temperature?
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