Methods of Heat Transfer

Question 1

3 Methods of Heat transfer

Answer 1

Conduction
Convection
Radiation

Question 2

• the process where heat is transferred thru a material without any movement of the material
• the direct flow of heat thru a material resulting from physical contact

Answer 2

Conduction

Question 2

in conduction, objects are ________

Answer 2

in contact with each other

Question 3

it often happens when energetic molecules bump into less energetic cool molecules

Answer 3

Conduction

Question 4

refers to the materials that conduct heat well ( best examples for this are metals)

Answer 4

Thermal conductors

Question 5

refers to the materials that conduct heat poorly ( best examples for this are wood, plastic, glass)

Answer 5

Thermal insulators

Question 6

2 ways to create good insulators:

Answer 6

1. small k and big d
2. ratio d/k called R factor (higher R factor, better insulator)

Question 7

other insulators like ___________ and _________ work by trapping air in small spaces where convection currents arise

Answer 7

goose down
styrofoam

Question 8

• refers to the flow of heat due to the movement of matter
• heat transfer between surface and adjacent fluid and any by the flow of fluid from one place to another, induced by temperature

Answer 8

Convection

Question 9

Difference in densities of fluids with different temperatures (WARM air RISES, COLD air FALLS) fall under this type of convection

Answer 9

Natural convection

Question 9

2 types of convection

Answer 9

1. Artificial
2. Natural

Question 9

Circulatory system (pumps blood) and Radiator pump (antifreeze) are under this type of convection

Answer 9

Artificial convection

Question 10

CONVECTION OR RADIATION.
heat from the sun reaches Earth without contact

Answer 10

Radiation

Question 11

CONVECTION OR RADIATION.
Movement of a Fluid

Answer 11

Convection

Question 12

Energy is transferred by __________

Answer 12

electromagnetic waves

Question 13

• refers to the transfer of energy via electromagnetic waves
• includes radio waves, microwaves, x-rays, infrared, and visible light

Answer 13

Radiation

Question 13

ice cubes emit ______________ radiation

Answer 13

very little

Question 14

TRUE/FALSE.
All bodies (objects) continually emit radiation

Answer 14

TRUE

Question 15

warm bodies, like human bodies emit ______

Answer 15

infrared radiation

Question 16

when the temperature of the body reaches 1000K, it starts to emit ___________

Answer 16

visible dull red light

Question 17

when the the temperature of the body reaches 1700K, it starts to emit ___________

Answer 17

white-hot light

Question 18

TRUE/FALSE/
Different objects react the same to radiation

Answer 18

FALSE. reacts differently

Question 19

-what color absorbs most of radiation
- a good absorber of radiation

Answer 19

Black

Question 19

what color absorbs little radiation

Answer 19

Silver, white, light colors

Question 19

an object that absorbs all radiation and hits it

Answer 19

blackbody

Question 20

TRUE/FALSE.
All objects emit and absorb radiation continually

Answer 20

TRUE

Question 21

good absorbers = _______

Answer 21

good emitters

Question 22

• no transfer medium required
• refers to the transfer of thermal energy thru matter of space by electromagnetic waves

Answer 22

Radiation

Question 23

Conduction: via __________

Answer 23

direct contact

Question 24

Convection: via __________

Answer 24

fluid

Question 25

Radiation: via ____________

Answer 25

electromagnetic radiation