Heat Transfer

Question 1

What are the two ways to increase an objects temperature?

Answer 1

1) expose it to something with a higher temp

2) do work on it

Question 2

More compression =

Answer 2

Higher temp

Question 3

As a gas expands, it’s temp

Answer 3

Decreases

Question 4

Energy in solids and liquids both have

Answer 4

KE and PE

Question 5

Energy given to solids and liquids substances increase what’s

Answer 5

Both KE & PE energies

Question 6

Internal energy

Answer 6

Sum of all energies in a substance

Question 7

Heat def

Answer 7

The transfers of energy from a substance with more to a substance with less

Question 8

Thermal equilibrium def

Answer 8

2 substance at the same temperature

- no heat is present

Question 9

Heat transfer def

Answer 9

The movement of energy from one substance to another

Question 10

First type of heat transfer

Answer 10

1) convection

Question 11

Convection def

Answer 11

The transfer of heat by buoyant from one substance to another

Question 12

Convection currents

Answer 12

Fluid flows in a specific direction

• heated fluid becomes less dense causing it to rise
• as fluid cools, it becomes more dense and sinks down

Question 13

Forced convection def

Answer 13

Physically moving the fluid

- stirring cream into coffee

Question 14

Sea breeze def

Answer 14

Air from above the water moves towards the land
- land is heated
See notes

Question 15

Land breeze

Answer 15

Movement of air from land out of water

Land cools down faster

See notes

Question 16

Water Temp does not change easily

Answer 16

*^

Question 17

Conduction

Answer 17

The transfers of heat between 2 objects in direct contact

Question 18

Atoms of warmer object transfers some KE to atoms of cooler object until

Answer 18

Equilibrium is achieved

Question 19

Conduction depends on the what

Answer 19

Material

Question 20

Insulator def

Answer 20

Slow heat transfer

Question 21

Insulator def

Answer 21

Wool
Insulation
Styrofoam
Best one: gasses/vacuum

Question 22

Conductors def

Answer 22

Fast heat transfer

Question 23

Example of conductors

Answer 23

Metals

- electrons are free to move about the metal

Question 24

In between conductors and insulators

Answer 24

Stone, wood, concrete, glass

Question 25

Radiation

Answer 25

Transfer of heat by electromagnetic waves

Question 26

Radiation spectrum =

Answer 26

Radar, micro, IR, visible, UV, X-Ray, Gamma

Question 27

Radiation travels as a packet of energy called a

Answer 27

Photon

Question 28

Everything emits

Answer 28

Radiation

- how not an object is determined what type of radiation is released

Question 29

Radiation does not need a what to travel through

Answer 29

A medium

Question 30

Net heat transfer def

Answer 30

How much energy is absorbing - energy emitting

Question 31

If emitting more =

Answer 31

Cooling

Question 32

If absorbing more =

Answer 32

Warming

Question 33

Specific heat def

Answer 33

Relative amount of heat needed to raise the temp of a substance

Question 34

Phase transition def

Answer 34

Changing from one state of matter to another

Question 35

Energy is used to break bonds not

Answer 35

Speed up atoms

Question 36

Latent heat of fusion def

Answer 36

Amount of heat transferred to an object to have it melt

Question 37

Latent heat of vaporization

Answer 37

Amount of water transferred to an object to have it boil

Question 38

Humidity drf

Answer 38

Mass of water vapor in the air per unit volume

Question 39

Saturation density def

Answer 39

,maximum humidity for a certain temp

Question 40

Relative humidity def

Answer 40

Humidity expressed as a% of saturation density

Question 41

Dew point def

Answer 41

Temp at which humidity condenses

Question 42

2nd law of thermodynamics

Answer 42

1) machines - some heat will always be lost in a device

2) amount of entropy in a system always increases