fire behavior 1-8

the minimum ignition energy (MIE) of most hydrocarbons is

.25 MJ.

what is the approximate average number of firefighter's killed in the line of duty each year from 2000-2010

100

from 2002-2011 approximately how many civilians were killed by each fire

3000-4000

how many firefighters died in the Sofa Super store fire in 2007 due to lack of understanding of fire dynamics

9

temperature to which a mixture of fuel gas and air must be raised to initiate combustion without any external heat source is called

Auto ignition

under NFPA classification, which presents the most significant threat of producing ignitable vapors at ambient conditions

Class IA

under NFPA classification, which presents the least significant threat of producing ignitable vapors at ambient conditions

Class IIIB

A Class D fire involves:

Combustible metals

which of the following sets a basic for classification of flammability of liquids

NFPA 30

investigators must first seek the _________ and then the _________ of a fire in order to ascertain what happened

Origin; cause

what is a turbulent flame

a flame oxidation occurring within a generalized area but not in a steady geometric pattern

what is a premixed flame

a flame where air is introduced before the point of combustion

what is a laminar flame

a flame with a clearly defined combustion zone

the open cups test of liquids flash point involves

a heating unit being adjusted to raise the liquids temperature slowly, the operator recording liquid temperature periodically, then introducing a pilot flame across the surface, the flash point being recorded as the temperature that occurred immediately before flash fire is witnessed

NFPA 921 defines fire as which

a rapid oxidation process which is a chemical reaction, resulting in the evolution of heat and light in varying intensities

which of the following describes and endothermic reaction

absorbs energy/heat

describe the endothermic process of pyrolysis

absorbs heat/energy

what is heat of gasification

amount of energy that is required to produce a unit of mass of flammable vapor from a combustible that is initially at ambient temperatures

increasing the oxygen concentration causes

an increase in temperature

a view factor method is

approximates the flame as a geometric shape and uses an average emissive power of the geometric object to estimate the heat flux to a target

what defines a gaseous state

atoms that collide but are not in a fixed arrangement and assume the shape of a container

three know conditions that can lead to firefighter fatalities are flashover, rollover and ________

backdraft

flammable liquids have a flash point (per NFPA30)

below 100 degrees Fahrenheit

flame spread of soundproofing used at the station night club was know to fire testing agencies and professionals, but was not considered during which phase

both installation and fire code inspection

heat release rates of pool fires are dependent on

both surface are exposed to air and heat combustion of the fuel

how will presence of char affect the burning rate of a fuel

burning rates will be slowed, and energy required increases

the variables to considered when determining a fuels heat release rate include, surface area, mass loss rate or burning rate, the heat of combustion

but no ignition temperature

class k fire involves what types of materials

certain cooking media such as vegetable and animal fats and oils

what is the term for carbonaceous material that has been burned of pyrolyzed and has a blackened appearance

char

the flow of heated gases, thus the convective heat transfer, aiding in the flame spread is know as

concurrent flow flame spread

in geometry of fuels, which shape of fuel surface will reflect the least imposed heat flux

convex

the flow of air entraining into combustion reaction that is going against the spreading flame is

counterflow flame

following thermophysical properties are termed thermal inertia

density, specific heat, and thermal conductivity

__________, including butadiene and neoprene, are items that have been created to match the properties of natural rubbers

elastomers

fire prevention professionals involved inspections are charged with identifying conditions that;

exceed design criteria for fire protection systems, adversely affect passive fire protection, hinder active fire protection and detection elements

under the federal hazardous substances act, ignitable liquids are classified as which of the following

extremely flammable, flammable, or combustible

class b fire involves which type of materials

flammable gasses and flammable or combustible liquids

what is a class 4 hazardous material per us department of transportation

flammable solid

what is the main measurement used when considering the ignitability of liquids

flash point

__________ are plastics created with pockets of air throughout the fuel

foams and cellular plastics

melting is a physical change of a substance

from solid to liquid

the fire triangle consists of what components

fuel, heat, oxygen

fire protection professionals must utilize a full knowledge of what topics

fuels and fuel geometry, detection and suppression

caution should be used when evaluating gasses beacuase

gases not listed as flammable can sometime ignite under certain conditions

following describes an exothermic reaction

gives off heat /energy

the ____________ of a material refers to the amount of energy emitted per unit of fuel mass consumed, and it varies by fuel

heat of combustion

________ is used to describe the amount of energy that is required to produce a unit mass of flammable vapor from a combustible that is initially at ambient temperatures

heat of gasification

the rate at which the heat energy is generated by burning

heat release rate

why do aerosol ignite easy

high surface to mass ratio

in the orientation of solid fuels, which will typically have slower flame spread under identical conditions

horizontal

cellulosic materials consist of

hydrocarbons

liquids evolving vapors that can undergo combustion with relative ease are consider to be

ignitable liquids

the four idea fire growth curves include all of the following except

infinite

the predominant factor that led to the large number of deaths at the Cocoanut grove fire was_______

inward swinging doors

The energy required to change a liquid to a vapor is

latent heat of vaporization

what is liquids flash point

lowest temperature of a liquid, as determined by specific laboratory tests, at which the liquid gives off vapors at a sufficient rate to support a momentary flame across its surface

the ________ is the loss of mass over time from the fuel's surface when undergoing combustion

mass burning flux

the ________, often referred to as the burning rate, is the rate at which the fuel is losing mass while undergoing combustion and is usually expressed in kilograms per second or grams per

mass loss rate m'

What is ignition temperature?

minimum temperature required for ignition of fuel gases under specific test conditions

following is not a material property that influences both ignition and flame spread

moisture

temperature is a measurement of

molecular movement

a class c fire involves what types of materials

natural and synthetic materials like rubber and plastics, which are energized by electrical circuits, wiring motors, and other equipment

should combined gas law be used to calculate the pressure in BLEVE

no, due to high pressure and unknow quantities of vapor/liquid in the container

class a fire involves what types of materials

ordinary cellulosic materials such as wood and paper as well as similar natural synthetic materials like rubber and plastics

what are fire investigations primarly tasked with identifying?

origin, cause, spread, responsibility and circumstances

smoldering combustion is characterized by

oxidation reaction in the solid phase that produces light and oxidation reaction in the solid phase that produces heat

what is the major source of fuel in upholstered furniture

polyurethane foam

what is the term used to describe the evaluation of conditions before emergencies

preplanning

study of fire dynamics helps to______

provide safety for humans and structures

solids undergo _______ as they chemically breakdown to become fuel gasses that can burn in the gas phase

pyrolysis

as altitude changes, the vapor pressure of liquid

remains the same

having a definite shape and volume describes what state of matter

solid

the standard time-temperature curve does not take into account what kinds of fuel that are common

synthetic materials

what is the autoignition temperature

temperature at which oxidation reactions will initiate within fuel/air mixtures without an outside pilot source

what is a liquids fire point

temperature at which the substance must be raised to produce sufficient vapors to sustain burning after the initial flash

what is the piloted ignition temperature

temperature required to produce the lower flammable limit and can be ignited in the presence of a piloted ignition source

flammability limits are dependent on which of the following

temperature, pressure, and oxygen concentration

what is a stoichiometric mixture

the exact proper mixture ( mass of each reactant) of chemical for a chemical reaction

smoke is define as

the gases, vapors, and small particles that come off burning substances

what is the upper explosive limit

the highest percentage of fuel to air where combustion can occur

the term fire dynamics refers to

the interrelationship of fuel, heat, oxygen, chemical reactions, and the physical world

what is the lower flammable limit

the percentage of air and fuel where the lowest amount of fuel will combust

flame spread refers to

the speed which the flame (oxidation zone) moves across a fuel's surface

miscibility and solubility are terms used interchangeably to describe which of the following

the tendency of materials to become solutions or to retain their initial characteristics

what is the effective heat of combustion

the visible, luminous body where the oxidation reaction is occurring

what is one factor responsible for the rapid fire development in today's built environment

the volume of commodities and synthetics

term for solids that absorb heat energy more readily and do not transfer it as quickly through the material to the opposite side

thermally thick

what is the term for the inability to absorb heat energy very well, resulting in quickly transferring heat from one side to the opposite side of material

thermally thin

plastics that are not cured or hardened during the manufacturing process and that soften and melt when exposed to heat are

thermoplastics

plastics that have been hardened into a defined shape during manufacturing and that when heated typically not soften or melt but produce char, are called

thermosetting plastics

nearly all metals burn under the right conditions

true

specific gravity of vapors and gases is

vapor density

what describes the pressure exerted by vapors leaving the liquid surfaces

vapor pressure

the autoignition temperature of liquids is

well above boiling point, ignition absent of an ignition, identified by raising the temperature of a liquid in a controlled environment until ignition occurs