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Flashcards in 3 Fire Behavior Deck (153)
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1
Q

The science of fire is an attempt to understand and control fire and involves both scientific and commonsense answers to the following questions

A

How does fire transform matter. How does fire spread

2
Q

When material burns a visible change occurs, generating what

A

Heat and light

3
Q

What occurs when a material or substance remains chemically the same but changes in size shape or appearance

A

A physical change

4
Q

What occurs when a substance changes from one type of matter into another.

A

Chemical change

5
Q

Reactions that absorb energy as they occur are called

A

Endothermic

6
Q

Reactions that give off energy as they occur are called

A

Exothermic

7
Q

Fire is what

A

And exothermic chemical reaction called combustion that releases energy in the form of heat and light

8
Q

If your potential energy is released during combustion and converted into what

A

Kinetic Energy

9
Q

Some solid fuels particularly those that are porous can char and undergo oxidation on the fuel surface. This oxidation is known as

A

Nonflaming or smoldering combustion

10
Q

The old combustion model composing of oxygen fuel and heat

A

Fire triangle

11
Q

The new fire behavior model which explains smoldering combustion comprising of heat fuel or reducing agent chemical change reaction and oxidizing agent

A

Fire tetrahedron

12
Q

The fire tetrahedron is comprised of four elements

A

Fuel. Auction. Heat. Self sustained chemical reaction

13
Q

The material or substance being oxidized or burned in the combustion process

A

Fuel, reducing agent

14
Q

In organic fuels such as hydrogen or magnesium do not contain what

A

Carbon

15
Q

Organic fuels contain what

A

Carbon

16
Q

Organic fuel can be for the divided into two categories

A

Hydrocarbon-based, cellulose based

17
Q

To key factors influencing the combustion process are

A

Physical state and its distribution or orientation

18
Q

Three physical states of matter which fuel may be found

A

Solid liquid or gas

19
Q

For flaming combustion to occur fuels must be in what state

A

Gaseous

20
Q

A fuel that has definite size and shape

A

Solid fuel

21
Q

A type of plastic that is not readily change its physical shape when exposed to heat

A

Thermosetting plastics

22
Q

When wood is first heated what is released as the wood dries

A

Water vapor

23
Q

As surface increases the more material is exposed to heat in this generates combustible pyrolysis products more quickly making the fuel easier to ignite is the explanation of what

A

Surface to mass ratio

24
Q

The distribution and orientation of a solid fuel, vertical/horizontal, relative to the source of heat also affects what

A

The way it burns

25
Q

A state of fuel that has mass and volume but no definite shape

A

Liquid fuel

26
Q

Gasoline has a specific gravity of what

A

Less than one

27
Q

Liquid fuels have a number of characteristics that contribute to their abilities to ignite and burn. These characteristics include the following

A
Solubility. 
Vaporization. 
Vapor pressure. 
Flashpoint. 
Flammable/combustible liquids. 
Surface area
28
Q

Flammable liquids have a flashpoint that is less than what temperature

A

Less than 100°F

29
Q

Combustible liquids have a flashpoint that are greater than what temperature

A

Greater than 100°F

30
Q

Transformation of a liquid to a vapor or gaseous state

A

Vaporization

31
Q

Pressure produced or exerted by the vapor that a liquid releases. As a liquid is heated this increases along with the rate of vaporization

A

Vapor pressure

32
Q

The temperature at which a liquid releases sufficient vapors to ignite but not sustain combustion, commonly indicate flammability hazard of liquid fuels

A

Flashpoint

33
Q

Extent to which a substance will mix with water

A

Solubility

34
Q

Substances that readily mix with water such as alcohol

A

Polar solvents

35
Q

Materials that are miscible in water will mix in

A

Any proportion

36
Q

Weight of a given volume of pure vapor or gas compared to the weight of an equal volume of dry air at the same temperature and pressure

A

Vapor density

37
Q

The most dangerous type of all fuel types

A

Gaseous fuel

38
Q

State of fuel that mass but no definitive shape or volume

A

Gaseous fuel

39
Q

A gas that has a vapor density less than one and rises

A

Methane

40
Q

Liquid petroleum gas tends to sink and has a vapor density less or greater than one

A

Greater than one

41
Q

Vapor density is generally specified at what temperature

A

68°F

42
Q

The primary oxidizing agent in most fires is what

A

Oxygen

43
Q

At normal ambient temperatures materials can ignite and burn at oxygen concentrations as low as what percent

A

14%

44
Q

Some petroleum-based materials will auto ignite during what condition

A

Oxygen concentrations are higher than 21%

45
Q

And industrial bleaching agent used to typically for paper manufacturing

A

Hydrogen peroxide

46
Q

many materials that do not burn at normal oxygen levels and burn readily and what type Of atmosphere

A

Oxygen enriched

47
Q

The fuel to air concentration range that supports combustion is called

A

The flammable range. Or explosive range

48
Q

Lowest Limit at which a flammable gas or vapor will ignite

A

Lel

49
Q

Upper limit at which flammable gas or vapor will ignite

A

UFL

50
Q

True/false. Variations in temperature and pressure can cause the flammable range to vary considerably

A

True

51
Q

Generally increases in temperature or pressure brought in the range of

A

Flammability

52
Q

Decreases in temperature and pressure does not narrow the flammable range. True/false

A

False it does narrow it

53
Q

Energy exists in two states

A

Potential and kinetic energy

54
Q

Potential energy is

A

The energy possessed by an object that may be released in the future

55
Q

The energy possessed by a moving object is

A

Kinetic energy

56
Q

Form of energy associated with the motion of atoms or molecules and capable of being transmitted through solid and fluid media by conduction convection and radiation

A

Heat

57
Q

Heat moves away from fuel that is burning toward what

A

Fuel that is not burning

58
Q

Flammable Range of methane

A

5% through 15%

59
Q

Flammable range of propane

A

2.1% -9.5%

60
Q

Flammable range of carbon monoxide

A

12% -75%

61
Q

Flammable range of gasoline

A

1.4% -7.4%

62
Q

Flammable range of diesel

A

1.3% -6%

63
Q

Flammable range of ethanol

A

3.3% -19%

64
Q

Flammable range of methanol

A

6% -35.5%

65
Q

There are two forms of ignition

A

Piloted ignition and autoignition

66
Q

This type of ignition occurs when a mixture of fuel and oxygen encounters and external heat source with sufficient heat energy to start the combustion reaction

A

Piloted ignition

67
Q

This type of ignition occurs without any external flame or spark to ignite fuel gases or vapors

A

Autoignition

68
Q

Temperature to which the service of a substance must be heated for ignition and self sustained combustion to occur

A

Autoignition temperature

69
Q

The autoignition temperature is always higher than what

A

The pilot ignition temperature

70
Q

The most common type of ignition is

A

Piloted ignition

71
Q

Heat energy usually comes from one or more of the following sources

A

Chemical. Mechanical. Electrical. Light. Nuclear. Sound

72
Q

The most common sources of heat that results in the ignition of fuel

A

Chemical and electrical and mechanical energy

73
Q

The most common source of heat in combustion reactions

A

Chemical heat energy

74
Q

Oxidation almost always results in the production of what

A

Heat

75
Q

Heating that occurs when a material increases in temperature without the addition of external heat

A

Self heating, or spontaneous heating

76
Q

For spontaneous ignition to occur the following set of circumstances must be met

A

Insulate of property of material must be so that it cannot dissipate as fast as it is being generated.
Rate of the production great enough to raise temperature to ignition point.
Available air supply adequate to support combustion

77
Q

Heat generated as electrical current passes through a conductor such as copper wire

A

Electrical heat energy

78
Q

Electrical heating can occur in several ways including the following

A

Resistance heating.
Overcurrent or overload.
Arcing.
Sparking

79
Q

Heat produced when electric current flows through a conductor

A

Resistance heating

80
Q

Unintended resistance heating

A

Overcurrent or overload

81
Q

High temperature luminesce electric discharge across a gap or through a medium such as charted insulation

A

Arcing

82
Q

Form of heat energy generated by friction or compression

A

Mechanical heat energy

83
Q

Movement that results in the generation of heat and or Sparks, created went to services move against each other

A

Heat of friction

84
Q

Energy created when a gas is compressed

A

Heat of compression

85
Q

In order for heats to be transferred from one object to another the two objects must be a different

A

Temperatures

86
Q

The transfer of heat from object to object is measured as

A

Energy flow overtime

87
Q

Transfer of heat within an object or to another object by direct contact, heat flow through and between solids

A

Conduction

88
Q

The transfer of heat energy for my fluid, liquid or gas, to a solid surface

A

Convection

89
Q

Transmission of energy as an electromagnetic wave such as lightwaves radio waves are x-rays without an intervening medium

A

Radiation

90
Q

All matter having a temperature above what will radiate heat energy

A

Absolute zero

91
Q

This type of he becomes the dominant Mode of heat transfer when a fire grows in size and he can have significant effect on the ignition of objects located some distance away

A

Radiant heat

92
Q

A wide range of factors influence radiant heat transfer including the following

A

Distance from heat source.
Temperature difference between source and material heated.
Collar and reflective qualities of heat source and material heated

93
Q

As temperature of the heat source increases the radiant energy increases by a factor of what

A

Increases by a factor to the fourth power

94
Q

Materials that absorbs heat but do not participate actively in the combustion reaction

A

Passive agents

95
Q

A passive agent that slows the absorption of heat energy in the ignition and combustion process

A

Fuel moisture

96
Q

Insulating materials retard the transfer of heat primarily by what

A

Slowing conduction from one body to another

97
Q

Type of heat transfer that is the cause of most exposure fires

A

Radiation

98
Q

A fourth method for heat transfer that has historically been used by the fire service is actually a combination of conduction and radiation rather than an independent method of heat transfer

A

Direct flame contact

99
Q

Free radicals combined with oxygen or with the elements that form the fuel material producing what

A

Intermediate combustion products, new substances

100
Q

Free radicals

A

Atom or group of atoms that has at least one unpaired electron, unstable and reactive

101
Q

Methane burns it creates what

A

Carbon and hydrogen

102
Q

When methane burns it creates what

A

Carbon monoxide and formaldehyde

103
Q

Surface combustion also involves oxidation at the surface of the actual material without initiation or continuation of the chemical change reaction found in what type of combustion

A

Flaming combustion

104
Q

Surface or smoldering combustion cannot be extinguished by chemical inhibition because

A

There are no flames and related chemical change reaction

105
Q

Halon agents extinguish fires by

A

Interrupting the chemical chain reaction

106
Q

An aerosol comprised of fire gases paper and solid particles

A

Smoke

107
Q

Carbon monoxide is the byproduct of

A

Incomplete combustion of organic materials

108
Q

Most common products of combustion encountered in structure fires

A

Carbon monoxide

109
Q

This is Produced in The combustion of materials containing nitrogen and a significant byproduct of the combustion of polyurethane foam

A

Hydrogen cyanide

110
Q

Product of complete combustion of organic materials is non-toxic but is an asphyxiant by displacing oxygen

A

Carbon dioxide

111
Q

This class of fire involves ordinary solid combustible materials such as would cloth paper rubber and plastics

A

Class a fires

112
Q

This class of fire involves my flammable and combustible liquids and gases such as gasoline oil and alcohol

A

Class B fires

113
Q

Class c fires involve what

A

Energize electrical equipment

114
Q

Combustible metals such as aluminum magnesium potassium sodium titanium and zirconium form this class of fire

A

Class D

115
Q

True/false. No single extinguishing agent effectively controls fires and all combustible metals

A

True

116
Q

Class K fires involve

A

Oils and greases normally found in commercial kitchens using deep fryer’s

117
Q

A process caused by class K extinguishing agents turning fats and oils into a soapy foam that extinguishes a fire

A

Saponification

118
Q

When sufficient oxygen is available for development is controlled by the characteristics and configuration of the fuel and is considered to be

A

Fuel controlled

119
Q

When fire development is limited by the air supply the fire is set to be

A

Ventilation controlled

120
Q

Four stages of fire development

A

Incipient. Growth. Fully developed. Decay

121
Q

Ignition occurs when all three elements of the fire triangle come together and combustion happens true or false

A

true

122
Q

Once combustion begins development of an incipient fire is largely dependent on the characteristics and configuration of

A

Fuel involved

123
Q

To draw in and transport as solid particles or gas, by the flow of a fluid

A

Entrain

124
Q

The ceiling Jet is otherwise known as

A

Mushrooming

125
Q

First affect caused by the transition into the growth stage is the amount of air that is

A

Drawn into the plume

126
Q

What determines the amount of air that is entrained and thus the amount of cooling that takes place

A

Location of fuel in relation to the compartment walls

127
Q

Thermal layering, isolated flames, rollover, and flashover are all found during what stage of fire

A

Growth stage

128
Q

Pocket flames that may be observed moving through the hot gas layer above the neutral plane is sometimes referred to as

A

Ghosting

129
Q

The rapid transition between the girls and fully developed by her stages but not a specific event like ignition

A

Flashover

130
Q

When the temperature in a compartment results in the simultaneous ignition of all the combustible contents in the space

A

Flashover

131
Q

Flashover temperature is typically occur between what

A

Between 900°F and 1200°F

132
Q

The temperatures associate with flashover is a range that usually correlates with the autoignition temperature of what, commonly produced gas

A

Carbon monoxide

133
Q

To develop flashover conditions the fuel must have sufficient

A

Heat energy

134
Q

A seal room might not provide enough what for a developing fire to reach flashover

A

Ventilation, oxygen

135
Q

Measurement of the amount of heat released when a material burns as stated in kilowatts or BTU

A

Heat release rate

136
Q

Most fires they grow beyond incipient stage become what controlled

A

Ventilation controlled

137
Q

The compartment fire will Decay as the fuel is consumed or as the oxygen concentration

A

Falls to the point where Flaming combustion can no longer be supported

138
Q

Instantaneous explosion or rapid burning of superheated gases that occurs when oxygen is introduced into a smoldering fire in a confined space

A

Backdraft

139
Q

Flammable products of combustion can accumulate within the compartment and if with in the flammable range they can ignite resulting in

A

Smoke explosion

140
Q

Ignition of accumulated flammable products of combustion

A

Smoke explosion

141
Q

A Backdraft will occur if the accumulated products of combustion are at or above their

A

Ignition temperature

142
Q

The following factors influence fire development with in a compartment

A
Fuel type. 
Availability and location of additional fuel. 
Compartment volume. 
Ventilation. 
Thermal properties of compartment. 
Ambient conditions. 
Effects of changing conditions.
143
Q

In a compartment fire the most fundamental fuel characteristics influencing fire development are

A

Mass and surface area

144
Q

A number of factors influence the availability and location of additional fuels including the following

A
Building configuration. 
Contents of building. 
Construction of the building. 
Interior finish materials. 
Fuel proximity and continuity. 
Fire location
145
Q

Amount of fuel present express quantitatively in terms of weight of fuel per unit area

A

Fuel load

146
Q

All things being equal a fire and a large compartment will develop more slowly than one in

A

A small compartment due to greater volume of air and material that must be heated

147
Q

Firefighters influence our behavior by doing one or more of the following actions

A
Reducing temperature. 
Eliminating fuel. 
Separating the fire from available fuel. 
Changing oxygen concentration. 
Interrupting chemical chain reaction
148
Q

When water is converted into steam at 212°F expands approximately how many times

A

1700 times

149
Q

Simplest method of fuel removal is

A

To allow the fire to burn until all fuel is consumed

150
Q

For fires involving pesticides or flammable liquid spills what might be the most appropriate action to extinguish

A

Allowing fuel to burn out because of possible environmental harm from water run off

151
Q

Example of oxygen exclusion to extinguish fire would be

A

Covering a cooking fire pan with a lid. Dry chemical extinguisher

152
Q

Halogenated agents are effective in extinguishing gas and liquid fuels because

A

They interrupt chemical change reaction and the fuels must flame to burn

153
Q

The primary duty of the fire inspector is to ensure

A

The life safety of all citizens and fire emergency services responders