Energy Transfered By Heating Flashcards

1
Q

Energy can be transferred by heating in 3 ways:

A

Radiation, conduction or convection

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2
Q

Thermal radiation is the transfer of energy by heating through __________

A

Infrared (electromagnetic) waves

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3
Q

Conduction and convection are energy transfers that involve the transfer of energy by __________

A

Particles

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4
Q

Conduction is the main form of energy transfer in ________

A

Solids

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5
Q

Convection is the main form of energy transfer by heating in _________ and _____

A

Liquids and gasses

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6
Q

Emission of __________ occurs in _______, __________ and _____. Any object can both absorb and emit _______________, weather or not conduction or convection is taking place.

A

Emission of Thermal radiation occurs in Solids, liquids and gasses Any object can both absorb and emit Thermal radiation, weather or not conduction or convection is taking place.

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7
Q

The _______ temperature difference, the faster energy is transferred between thermal energy stores of an object and its surroundings.

A

Bigger*

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8
Q

What can thermal radiation also be called?

A

Infrared (IR) radiation

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9
Q

All objects are ________ emitting and absorbing Infrared radiation

A

Continually*

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10
Q

An object that’s hotter than it’s surroundings admits More/Less radiation than it absorbs (as it cools down)

A

More (not less)

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11
Q

An object that’s colder than it’s surroundings absorbs More/less radiation than it emits (as it warms up)

A

More*

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12
Q

Can you feel infrared radiation?

A

Yes (eg: standing near a fire)

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13
Q

Do some colours and surfaces absorb and emit radiation better than others?

A

Yes

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14
Q

In a sold particles are held ______ together. So when one particle vibrates, it collided a with other particles near by and the vibrations pass quickly from particle to particle.

A

Tightly/ Close

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15
Q

Thermal conduction is:

A

The process where vibrating particles transfer energy from their kinetic energy store to the kinetic energy store of the neighbouring particles

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16
Q

This process ______ throughout the solid and gradually passed all the way through the solid, causing a rise in __________ at the other side of the solid. It’s then usually transferred to the thermal energy stores of the surroundings or anything touching the object

A

Continues* Temperature*

17
Q

Name the main form of energy transfer by heating in a solid

A

Conduction

18
Q

When does convection occur?

A

When the more energetic particles move from the hotter region to the cooler region

19
Q

Convection simply _______ happen in solids because the particles _______ move apart (they can only vibrate)

A

Cannot* Can’t *

20
Q

In what shape containers is convection most efficient?

A

Round/square

21
Q

Why do hot fluids rise in a convection current?

A

Because heated fluids expand, becoming less dense

22
Q

Convection occurs mainly in ________

A) fluids
B) solids
C) Gasses

A

A) fluids

23
Q

Heat = more energy in the particles kinetic energy store

More heat = ?

A

They move quicker

24
Q

Where do heated/ energetic particles move to?

A

The cooler area

25
Q

The high energy particles in a hotter region are more _________

A

Spread out**

26
Q

What happens to a fluid in a warmer region?

A

It expands and becomes less dense

27
Q

What’s a convection current?

A

Are a flowing fluid or gas that is moving because there is a temperature or density difference within the material

28
Q

How do you reduce convection?

A

Stop the free flow of air/fluids

Eg: sleep under a blanket

29
Q

What does conduction and convection have in common?

A

They both involve particles gaining kinetic energy

30
Q

To reduce energy transfers away from a system by conduction use materials with a low/high thermal conductivity

A

Low*

31
Q

Insulation such as clothes, blankets and foam cavity wall insulation, all work by trapping pockets of air. The air can’t move so the energy has to conduct very slowly/fast.

A

Slowly*

32
Q

A black surface is better/worse at absorbing and emitting IR radiation than a white one

A

Better*

33
Q

A matte (dull) surface is worse/better at absorbing and emitting radiation than a shiny one

A

Better*

34
Q

Why would hot water in a black mug cool down faster than if the mug was white?

A

Because a black surface absorbs and emits infrared radiation better than white surface.