Ch 1 Fire Dynamics Flashcards
1
Q
Fire can take various forms, but all fires involve a heat producing chemical reaction between some type of fuel and an_______, most commonly oxygen in the air
A
Oxidizer
2
Q
A __________ Change occurs when a substance remains chemically the same but changes in size, shape, or appearance
A
Physical
3
Q
_______ is a chemical reaction involving the combination of an oxidizer, such as oxygen in the air, with other materials
A
Oxidation
4
Q
_____ Is the capacity to perform work
A
Energy
5
Q
Fuels have a certain amount of potential energy before they are ignited, based on their chemical composition. This potential energy available for release in the combustion process is known as the__________
A
Heat of combustion
6
Q
Energy is measured in joules in the international system of units.The quantity of heat required to change the temperature of 1 pound of water by 1°C is ________
A
4.2 Joules
7
Q
A _________ Is the amount of heat required to raise the temperature of 1 pound of water by 1°F
A
British thermal unit
8
Q
Reactions that emit energy as they occur are____________
A
Exothermic reactions
9
Q
Reactions that absorb energy as they occur are________
A
Endothermic reactions
10
Q
Chemical reaction in which a substance absorbs heat
A
Endothermic reaction
11
Q
A ________ Chemical chain reaction must also be present for a fire to occur
A
Uninhibited
12
Q
___________ is the most common form of ignition and occurs when a mixture of fuel and oxygen encounter an external heat source with sufficient heat or thermal energy to start the combustion reaction
A
Piloted ignition
13
Q
_________ occurs without any external flame or spark to ignite the fuel gases or vapors
A
Auto ignition
14
Q
Moment when a mixture of fuel and oxygen encounters an external heat source with sufficient heat or thermal energy to start the combustion reaction
A
Piloted ignition
15
Q
__________ is the minimum temperature at which a fuel in the air must be heated in order to start self sustained combustion
A
Auto ignition temperature
16
Q
_______ combustion occurs more slowly and at a lower temperature, producing a smoldering glow in the material surface
A
Non-flaming
17
Q
______ Combustion is referred to as a fire
A
Flaming
18
Q
Smoke is an______ comprised of gases, vapor, and solid particulates
A
Aerosol
19
Q
Complete combustion of_____ in air results in the production of heat, light, water vapor, and carbon dioxide
A
Methane
20
Q
This product of combustion is a colorless, odorless gas
A
Carbon monoxide
21
Q
This product of combustion is a colorless gas with a pungent irritating odor that is highly irritating to the nose
A
Formaldehyde
22
Q
This product of combustion is a colorless, toxic, and flammable liquid below 79°F produced by the combustion of nitrogen bearing substances
A
Hydrogen cyanide
23
Q
This product of combustion is a reddish brown gas or yellowish brown liquid which is highly toxic and corrosive
A
Nitrogen dioxide
24
Q
This product of combustion is small particles that can be inhaled and deposited in the mouth, trachea, or the lungs
A
Particulates
25
This product of combustion is a colorless gas with a choking or suffocating odor
Sulfur dioxide
26
CO combines with hemoglobin about_____ times more effectively than oxygen does
200
27
__________ A toxic and flammable substance produced in the combustion of materials containing nitrogen, is also commonly found in smoke, although at lower concentrations than CO
Hydrogen cyanide
28
Hydrogen cyanide is___ times more toxic than CO
35
29
More than ______irritants in smoke have been identified including hydrogen chloride, formaldehyde, and acrolein
20
30
_______ Energy is the most common source of heat in combustion reactions
Chemical
31
__________ A form of oxidation, is a chemical reaction that increases the temperature of a material without the addition of external heat
Self Heating
32
Self heating can lead to_____, which is ignition without the addition of external heat
Spontaneous ignition
33
An _____ is a high temperature luminous electric discharge across a gap or through a medium such as charge insulation
Arc
34
Heat is generated when gas is _______
Compressed
35
The transfer of heat from one point or object to another is part of the study of ___________
Thermodynamics
36
Fuel is the oxidized or___ material or substance in the combustion process
Burned
37
The fuel in a combustion reaction is known as the _______
Reducing agent
38
Charring of modern protective clothing fabric begins at this temperature
>572°F
39
Human skin is instantly destroyed at this temperature
162°F
40
Human skin receives a first-degree burn injury at this temperature
118°F
41
Temperatures inside a post flashover room fire are of this temperature
> 1112°F
42
The peak heat release rate during unconfined burning of a dry Christmas tree is
3000-5000 kilowatt
43
The peak heat release rates during unconfined burning of polyurethane sofa is______
3120 kilowatts
44
Fuel and is being oxidized or burned during combustion
Reducing agent
45
Vapor density of methane
.55
46
Vapor density of propane
1.52
47
Vapor density of carbon monoxide
.96
48
Ignition temperature of methane
1004°F
49
Ignition temperature of propane
842°F
50
Ignition temperature of carbon monoxide
1128°F
51
________ Is the minimum temperature at which a liquid gives off sufficient papers to ignite, but not sustain combustion, in the presence of a piloted ignition source
Flashpoint
52
Liquid fuels that vaporize sufficiently to burn at temperatures under______ present a significant flammability hazard
100°F
53
Flammable liquids called______ such as alcohols will mix readily with water
Polar solvents
54
Specific gravity of gasoline
.72
55
Specific gravity of diesel
1.00
56
Specific gravity of ethanol
.78
57
Specific gravity of methanol
.79
58
Flash point of gasoline
-36°F
59
Flashpoint of diesel
125°F
60
Flashpoint of ethanol
55°F
61
Flashpoint of methanol
52°F
62
Auto ignition temperature of gasoline
853°F
63
Auto ignition temperature of diesel
410°F
64
Auto ignition temperature of ethanol
689°F
65
Auto ignition temperature of methanol
867°F
66
When placed in an oxygen enriched atmosphere of approximately _______ oxygen, nomex ignites and burns vigorously
31%
67
At normal ambient temperatures, materials can ignite and burn at oxygen concentrations as low as _______
15%
68
The flammable range of carbon monoxide
12%- 75%
69
Flammable range of methane
5%-15%
70
Flammable range of propane
2.1%-9.5%
71
Flammable range of gasoline
1.4%-7.4%
72
Flammable range of diesel
1.3%-6%
73
Flammable range of ethanol
3.3%-19%
74
Flammable range of methanol
6%-35.5%
75
Complete oxidation of ______ releases the elements needed to create carbon dioxide and water as well as release energy in the form of heat and light
Methane
76
___________ occurs when an extinguishing the agent, such as dry chemical or halon replacement agent, interferes with the chemical reaction, forms a stable product, and terminates the combustion reaction
Chemical flame inhibition
77
A visual indicator that a fire is leaving the incipient stage is __________
Flame height
78
The drawing in and transporting of solid particles or gases by the flow of a fluid
Entertainment
79
The appearance of_______ is sometimes an immediate indicator of flashover
Isolated flames
80
Most residential fires that develop beyond the incipient stage become _________
Ventilation Limited
81
Rapidfire development refers to the rapid transition from the ______stage or early decay stage to a ventilation limited, fully developed stage
Growth
82
Rapid transition from the growth stage to the fully developed stage is known as ________
Flash over
83
As a flash over occurs, gas temperatures in the room reach______ or higher
1100°F
84
A significant indicator of flash over is_______
Rollover
85
The auto ignition temperature of CO, the most abundant fuel gas created in most fires, is approximately ________
1100°F
86
This level of neutral plane could indicate that the compartment has not yet ventilated or that flashover is approaching
Mid level neutral plane
87
This level of neutral plane may indicate that a fire is in the early stages of development
High neutral plane
88
This level of neutral plane may indicate that the fire is reaching back draft conditions
Very low level neutral plane
89
There are two main types of fully developed fires; ventilation limited and ________ fires
Fuel limited
90
Wind speeds as low as _____can create wind driven fire conditions
10 mph
91
A ________ occurs when a mixture of unburned fuel gases and oxygen comes in contact with an ignition source
Smoke explosion
92
Form of fire gas ignition; the ignition of accumulated flammable products of combustion and air that are within their flammable range
Smoke explosion
93
Unprotected engineered steel and wooden trusses can fail after 5 to__ minutes of exposure to fire
10
94
For steel trusses, _____ is the critical temperature of steel the temperature at which steel begins to weaken
1000°F
95
Bowstring trust roof systems constructed before the late 1960s have a common code deficiency; the bottom cord members may have inadequate __________ to support code prescribed rough loads
Tensile strength
96
A ______ occurs when a substance changes from one type of matter in to another, such as two or more substances combining to form compounds
Chemical reaction
97
The auto ignition temperature of a substance is always higher than it’s ______ temperature
Piloted ignition
98
Carbon monoxide as a toxic and flammable product of the _________combustion of organic materials
Incomplete
99
Carbon dioxide is a product of _____ combustion of organic materials
Complete
100
_______ heat can become the dominant mode of heat transfer as the fire grows in size and can have a significant effect on the ignition of objects located some distance from the fire
Radiant
101
_______ Is a common cause of exposure fires
Radiation
102
Fuel that is being oxidized or burned during combustion
Reducing agent
103
______ Is the rate at which energy transfers
Power
104
____ Is the energy released per unit of time as a fuel Burns and is usually expressed in kilowatts or megawatts
Heat release rate
105
______ is the common term used to describe the gaseous state a a fuel that would normally exist as a liquid or a solid at a standard temperature and pressure
Vapor
106
Pyrolysis of wood begins at a temperature below ____
400°F
107
At normal ambient temperatures, materials can ignite and burn at oxygen concentrations as low as____
15%
108
When placed in an oxygen enriched atmosphere of approximately_____ oxygen, nomex ignites and burns vigorously
31%
109
The____ Is the minimum concentration of your paper and air the supports combustion
Lower explosive Limit
110
The _____ Is the concentration above which combustion cannot take place
Upper explosive limit
111
When flames reach ______ high, radiated heat begins to transfer more heat than convection
2.5 feet
112
The fire is said to be in the______ stage until the fires heat release rate has reached its peak, either because of lack of fuel or a lack of oxygen
Growth
113
________ Is the tendency of gases to form and two layers according to temperature, gas density, and pressure
Thermal layering
114
The interface between the hot gas layers and cooler layer of air is commonly referred to as the ____because the net pressure is zero, or neutral, what are the layers meet
Neutral plane
115
During flashover, the volume of burning gases can increase from approximately 1/4 to ______of the rooms upper volume to fill the rooms entire volume and extend out of any openings from the room
1/2
116
The flow path is comprised of two regions, the ambient airflow in and the hot exhaust flow out. The flow is always _____ due to pressure differences where the ambient air flows toward the seat of the fire and reacts with the fuel
Undirectional
117
The total quantity of combustible contents of a building, space, or fire area is referred to as the_____
Fuel load
118
The ______of a structure are often the most readily available‘s fuel source, significantly influencing fire development in a compartment fire
Contents
119
_______ Describes the meeting point between fire science, materials science, fluid dynamics of gases, and heat transfer
Fire dynamics
120
_______ is the study of matter and energy and includes chemistry and physics
Physical science
121
When comparing Joules and BTU, blank, _______ j=1BTU
1055
122
Smoke is the product of ______
Incomplete combustion
123
Carbon monoxide is a toxic and flammable product of the incomplete combustion of _______materials
Organic
124
Hydrogen cyanide, a toxic and flammable substance produced in the combustion of materials containing ______
Nitrogen
125
Hydrogen cyanide is a significant byproduct of the combustion of_____ used in many household furnishings
Poly urethane foam
126
Carbon dioxide is a product of ________combustion of organic materials
Complete
127
_______ Is the measurement of the average kinetic energy in the particles of a sample of matter
Temperature
128
Friction or compression generates _______energy
Mechanical
129
The rate at which heat transfers is related to the temperature differential of the bodies and the _____of the materials involved
Thermal conductivity
130
Copper will conduct heat more than ______times faster than steel
Seven
131
Steel is nearly _____times as thermally conductive as concrete
40
132
All compartment fires begin in the incipient stage as ____ fires
Fuel limited
133
The energy released in fire is directly proportional to the amount of ______ available for combustion
Oxygen
134
_______ Is the place where fire dynamics in building construction interact
Structure fire
135
Physical science is the study of matter and energy and includes___&_____
Chemistry, physics
136
______ occurs when a force is applied to an object over a distance or when a substance undergoes a chemical, biological, or physical change
Work
137
Forms of energy are classified as either ___or ____
Potential, kinetic
138
______ Energy represents the amount of energy that an object can release at some point in the future
Potential
139
Fuels have a certain amount of potential energy before they are ignited, based on their _________
Chemical composition
140
_______ Energy is the energy that a moving object possesses
Kinetic
141
Exothermic reactions _____ energy while endothermic reactions ______ energy
Release, absorb
142
The fire tetrahedron model includes the _______ to explain flaming or gas phase combustion
Chemical chain reaction
143
In solids, offgassing is a chemical change known as ______, in liquids, a physical change called _____
Pyrolysis, vaporization
144
______ ignition involves the introduction of an external ignition source, while _____ occurs under special conditions without the heat of a spark or other source
Piloted, autoignition
145
Auto ignition temperature is the _____ temperature at which a fuel in the air must be heated in order to start self sustained combustion
Minimum
146
There are two modes of combustion; _____and _____
Non-flaming, flaming
147
Flaming combustion is commonly referred to as______
Fire
148
_______ combustion occurs when a gaseous fuel mixes with oxygen and the correct ratio and heats to ignition temperature
Flaming
149
_____ Is where the combustion process begins
Ignition
150
_____ It is an aerosol comprised of gases, vapor, and solid particulates
Smoke
151
Smoke is the product of______
Incomplete combustion
152
Complete combustion of methane in air results in the production of heat, light, water vapor and _______
Carbon dioxide
153
Gas is such as carbon monoxide are generally colorless, while ______ and _____ give smoke its varied colors
Vapor, particulates
154
Concentrations of the products of combustion and or low oxygen concentration can cause ________
Asphyxiation
155
________ Is a toxic and flammable product of the incomplete combustion of organic materials
Carbon monoxide
156
________ Is a colorless, odorless gas present at almost every fire
Carbon monoxide
157
________ Is a sometimes a little condition in which carbon monoxide molecules attached to hemoglobin, decreasing the bloods ability to carry oxygen
CO poisoning
158
Incomplete combustion of substances that contain nitrogen and carbon produce _____
HCN
159
HCN is a significant byproduct of the combustion of _____ used in many household furnishings
Poly urethane foam
160
______ In smoke are substances that cause breathing discomfort and information of the eyes, respiratory tract and skin
Irritants
161
Smoke also contains significant amounts of _______in the form of solid and liquid particulates and gases
Unburned fuel’s
162
_____ is the measurement of heat
Temperature
163
A dangerous misconception is that temperature is an accurate predictor or measurement of ______
Heat transfer
164
____ Energy is the most common source of heat in combustion reactions
Chemical
165
The _____ process almost always results in the production of thermal energy
Oxidation
166
This form of electrical heating is an electric current flowing through a conductor produces heat
Resistance heating
167
This example of electric heating is when the current flowing through a conductor exceeds its design limits
Overcurrent or overload
168
This example of electrical heating is when an Electric arc occurs, luminous particles can form and spider away from the point of arcing
Sparking
169
Heat is ____ when a gas is compressed
Generated
170
Heat transfer from the initial fuel package to other fuels in and beyond the area of fire origin affects the growth of any fire and is part of the study of______
Fire dynamics
171
Heat transfers from warmer objects to cooler objects because heated materials will naturally return to a state of _______ in which all areas of an object are a uniform temperature
Thermal equilibrium
172
The rate at which heat transfers is related to the temperature differential of the bodies and the _____ of the materials involved
Thermal Conductivity
173
_____ Occurs when a material is heated as a result of direct contact with a heat source
Conduction
174
_____ Slow the conduction of heat from one solid to another
Insulating materials
175
____ do not conduct heat very well because their molecules are relatively far apart
Gases
176
_____ Is the transmission of energy as electromagnetic waves, such as light waves, radio waves, or x-rays without an intervening medium
Radiation
177
______ Can become the dominant mode of heat transfer as the fire grows in size and can have a significant effect on the ignition of objects located some distance from the fire
Radiant heat
178
Radiation is a common cause of______
Exposure fires
179
_____ Is the oxidized or burned material or substance in the combustion process
Fuel
180
Fuels may be ____ or ___
In organic, organic
181
Most common fuels are _____containing carbon and other elements
Organic
182
The fuels ______ is the total amount of thermal energy released when a specific amount of that fuel burns
Heat of combustion
183
Another way to describe _____ is the rate at which energy converts from one form to another
Power
184
The standard international unit for power is the _____
Watt
185
When a fuel is heated, ____ is being performed
Work
186
The prefix kilo indicates a multiple of _____ and mega indicates a multiple of ______
Thousands, millions
187
For ______ combustion to occur fuels must be in the gaseous state
Flaming
188
______ Describes the density of gases in relation to air
Vapor density
189
______ Have mass and volume but no definite shape except for a flat surface or the shape of their container
Liquids
190
The _____ of a gas provides an indication of where a gas will collect at an incident
Vapor density
191
_____\ Is the ratio of the mass of a given volume of liquid compared to the mass of an equal volume of water at the same temperature
Specific gravity
192
 The pressure that vapors escaping from a liquid exert is known as_______
Vapor pressure
193
_____ Indicates how easily a substance will evaporate into air
Vapor pressure
194
The ______ Of the substance in the amount of thermal energy applied to it determines the rate of vaporization
Vapor pressure
195
The _____ Or ease with which a liquid gives off vapor influences how easily it can ignite
Volatility
196
______ Is the temperature at which a piloted ignition of sufficient vapors will be in a sustained combustion reaction
Fire point
197
______ is commonly used to indicate the flammability hazard of liquid fuels
Flashpoint
198
_____ Describes the extent to which a substance will mix with water
Solubility
199
Materials that are ____ in the water will mix in any proportion
Miscible 
200
Liquids that are _____ than water or more difficult to extinguish using water as the sole extinguishing agent
Less dense
201
Today, flexible ______ is one of the most common materials used in upholstered furniture
Polyurethane foam
202
Solid fuels have a definite shape and size which significantly affects how easily they ignite. The primary consideration is the surface area of the fuel in proportion to its mass called the_____
Surface to mass ratio
203
The ______ of a liquid indicates the temperature at which the liquid will ignite temporarily, while the _____ indicates the temperature at which a liquid once ignited will continue to burn
Flashpoint, fire point
204
The proximity and _____ of a solid fuel relative to the source of heat also affects the way the fuel burns
Orientation
205
Oxygen and the air is the _____ agent in most fires
Primary oxidizing
206
Normal air consist of about _______percent oxygen
21
207
At normal ambient temperatures, materials can ignite and burn at oxygen concentrations as low as ______ percent
15
208
For combustion to occur after a fuel converts into a gaseous state the fuel must be mixed with air in the proper ratio. The range of concentrations of the fuel vapor and air is called the _______
Flammable explosive range
209
The _____is a relatively narrow band of conditions at which a mixture of fuel vapors and air Wilburn
Flammable range
210
As flaming combustion occurs the molecules of a fuel gas and oxygen break apart to form _______
Free radicals
211
The elements released when _____ molecules breakdown recombine with oxygen in the air to form CO2 and H2O
Methane
212
At various points in the combustion of methane, this process results in production of ____ and _____ which are both flammable and toxic
Carbon monoxide, formaldehyde
213
When sufficient oxygen is available for flaming combustion, the fire is said to be ______
Fuel limited
214
Under fuel limited conditions the fuels characteristics such as ___ and configuration control fire development 
Heat release rate
215
All compartment fires began in the incipient stage as _____ fires
Fuel limited
216
Once the fire reaches the _____ stage the fire will either remain fuel limited if there is enough oxygen to support continued growth or the fire will consume the available oxygen and become ventilation limited
Growth
217
A _____ Fire will usually progress through the stages of fire development in order
Fuel limited
218
______ Or a free burn condition provides the most basic fire growth curve
Open burning
219
Open burning is representative of a ______ fire, such as a campfire, a pile of wood pallets, or sofa and a large open empty warehouse
Fuel limited
220
The _____ Stage is where a fire begins
Incipient
221
Once ignition occurs in the combustion process begins development in the incipient stage depends largely upon the ______ and ______ of the fuel involved
Characteristics, configuration
222
The hot gases in the plane rise until they encounter the ceiling and then begin to spread horizontally, this flow of fire gases is called the _____
Ceiling jet
223
During a _____ stage occupants can safely escape from the compartment and a portable extinguisher or small hose line can safely extinguish the fire
Incipient
224
When flames reach ____feet high radiated heat begins to transfer more heat than convection
2.5
225
Rapidfire development usually occurs during the ___ stage
Growth
226
Understanding fire dynamics is largely an understanding of everything that can happen during the ____ stage
Grothe
227
______ fires draw air from all sides and the entrainment of air cools the plume of hot gases reducing flame length and vertical extension
Unconfined
228
Thermal layering is the tendency of gases to form into layers according to temperature, gas density and ______
Pressure
229
Changes in ventilation and ______ can significantly alter thermal layering
Flow path
230
The ______ Exist at openings were hot gases exit and cooler air enters the compartment
Neutral plane
231
_______ development refers to the rapid transition from the growth stage or early decay stage to a ventilation limited fully developed stage
Rapidfire
232
Flash over typically occurs during the fire‘s ______ stage
Growth
233
At the floor level a heat flux of approximately _____ is also typical of rollover conditions at the start of the flashover
20kW/m2
234
NIST testing conducted in 2013 has shown the SCBA face pieces begin to fail after five minutes of exposure to a heat flux of _____
15kW/m2
235
Observing the ______ from outside a structure can provide indications of the behavior of the fire within
Neutral plane
236
To some degree, the violence of a Backdraft depends upon the extent to which the _______ is confined
Fuel air mixture
237
The ______ stage occurs when the heat release rate of the fire has reached its peak because of lack of either fuel or oxygen
Fully developed
238
There are two main types of fully developed fires;____and _____ fires
Ventilation limited, fuel limited
239
The ______ Limits the peak heat release rate in a fuel limited fully developed fire
Available fuel
240
_________ Usually occurs when fires are not contained within compartments such as wildland fires, vehicle killer fires or fires burning in collapsed structures
Fuel Limited full development
241
To reduce the risk of the unpredictable window failure firefighters must transition the fire from _____ limited to ______ limited
Ventilation, fuel
242
A fire is said to be in the _____ stage when it runs out of either fuel or oxygen
Decay
243
When a fire enters a ______ state of decay this stage is not necessarily the last stage of the fires development
Ventilation limited
244
______ Are essentially composed of individual compartments connected by hallways, stairways, or opening such as doorways
Structures
245
In a structure fire the method by which the fire receives the needed oxygen to sustain the combustion reaction occurs through one or many ______
Flow paths
246
In a structure fire, the _____ and ____ determine the available flow path
Floor plan, openings within the structure
247
____ Occurs when a structural member fails usually because of exposure to heat and introduces a new source of oxygen to the fire
Unplanned ventilation
248
Wind driven conditions can occur in any type of structure. Wind speeds as low as ______ can create wind driven fire conditions
10mph
249
Most ______ rate the various construction types according to how long each construction type maintains its structural integrity over a certain period of time
Building codes
250
Building ______ is the layout of the various open spaces in a structure
Compartmentation
251
Any open space with no complete fire barrier dividing it is considered a_____-
Compartment
252
A_________ Is the place where fire dynamics in building construction interact
Structure fire
253
In single-family residential structures, the square footage of houses has increased over _____ between 1973 and 2008
150%
254
Unprotected engineered steel and wooden trusses can fail after ____ minutes of exposure to fire
Five to ten
255
Bowstring truss roof systems constructed before the late ___\have a common code deficiency; the bottom cord members may have an adequate tensile strength to support code prescribed roof loads
1960s
256
Buildings under construction with exposed wooden framing are often thought of as the equivalent of a ______
Vertical lumberyard
