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Flashcards in Heat Transfer Deck (18)
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0
Q

Conduction

A

The energy is passed from one vibrating atom to the next

1
Q

What are all metals

A

Conductors however some are better than others

2
Q

Name given to process of convection

A

Convection current

3
Q

Convection

A

Hot liquids and gases expand and rise while the cooler liquids or gases fall

4
Q

What can infra red rays travel through and at what speed

A

A vacuum at the speed of light

5
Q

Radiation

A

Energy is transferred by infra-red rays

6
Q

What are poor radiators and absorbers

A

Shiny silver surfaces

7
Q

What are good absorbers and radiators

A

Dull black surfaces

8
Q

More energy is radiated

A

The hotter the object is

9
Q

Conduction is when heat travels through

A

A solid

10
Q

In conduction heat is passed on by

A

Vibrations

11
Q

When a solid is hot

A

It’s vibrations are bigger because it has more energy

12
Q

Heat is carried by

A

Free electrons

13
Q

Conduction experiments

A

Thermal conductivity bars
Wire gauze in iced water
Paper on wood and brass

14
Q

How does a convection current work

A

When a fluid is heated it expands and becomes less dense and so will float above cooler fluids

15
Q

Convection experiments

A

Potassium magnate in water

Smoke and candle

16
Q

When does an object absorb thermal radiation

A

When it’s cooler than its surroundings

17
Q

When does an object emit thermal radiation

A

When it is hotter than its surroundings