FLETC WRITTEN EXAM 4 QUESTIONS
WITH CORRECT ANSWERS
Three Types of Explosions - Correct Answers -Mechanical
Chemical
Nuclear
High Explosive - Correct Answers -Explosive which normally requires a blasting cap for
initiation and once initiated produces a supersonic detonation with a shattering or
brisant effect
Detonate without confinement, doesn't need container
Low Explosive - Correct Answers -Explosive, which when unconfined, responds to
initiation by deflagration or burning and produces a pushing effect
Transitions from deflagration to detonation when confined
Incendiary Explosive - Correct Answers -Explosive designed to start fires or destroy
sensitive equipment
Detonation - Correct Answers -Supersonic combustion that propagates through shock
compression generating exothermic heat and an accompanying blast wave
Deflagration - Correct Answers -A subsonic combustion that propagates through
thermal conductivity
Effects of an Explosion - Correct Answers -Thermal
Blast Pressure
Fragmentation
Thermal Effect - Correct Answers -Usually seen as a bright flash or fireball at the
moment of detonation
May cause localized ignition of highly combustible materials
Generally least damaging of the three effects
,Blast Pressure Effect - Correct Answers -Very hot gasses (between 3,000 and 7,000
degrees Fahrenheit) expand out from the point of detonation at supersonic velocities
(up to 20,000 mph)
The further the pressure wave travels, the less power it has
Most powerful and destructive/deadly of the effects
When taking place in a confined area, it can amplify the original blast wave
Two Phases of Blast Pressure - Correct Answers -Positive Phase
Negative Phase
Positive Phase of Blast Pressure - Correct Answers -Pressure wave moving outward
from the point of detonation
Negative Phase of Blast Pressure - Correct Answers -Partial vacuum is created near
the epicenter due to the outward movement of air and the consumption of oxygen from
the combustion process
4 Types of Injuries Sustained During a Blast - Correct Answers -Primary Blast Injury
Secondary Blast Injury
Tertiary Blast Injury
Quaternary Injury
Primary Blast Injury - Correct Answers -Caused by direct effects of blast
Secondary Blast Injury - Correct Answers -Caused by propelled fragmentation (most
deadly)
Tertiary Blast Injury - Correct Answers -Occurs when a casualty's body is propelled by
the blast against the ground or stationary objects
Quaternary Injury - Correct Answers -Any other injuries (burns and crush injuries)
Three Mechanisms of Primary Blast Injury - Correct Answers -Implosion
Spalling
Inertial Effects
Implosion - Correct Answers -Occurs when blast impacts the human body by
compressing air-filled cavities in the body and causes tissue damage as compressed air
stretches, tears, and ruptures internal organs and tissues
Spalling - Correct Answers -Describes tissue injury caused when blast wave rapidly
changes velocity as it moves through tissues of different densities
, Blast Lung - Correct Answers -Severe form of pulmonary contusion, crushed lung tissue
fills with blood and cannot exhange oxygen
Inertial Effects - Correct Answers -Injury occurring when connected tissues of different
densities move at different velocities
Progressive Collapse - Correct Answers -Refers to the spread of an initial local failure
from element to element, eventually resulting in a disproportionate extent of collapse
relative to the area of initial blast damage
Two Types of Progressive Collapse - Correct Answers -Pancaking
Cascading
Pancaking - Correct Answers -Occurs when an explosion destroys a structural member
or members, causing floor directly above destroyed members to collapse and the floor
above that to collapse and so on
Cascading - Correct Answers -Collapsing of a series of bays from the destruction of one
or few bays
Fragmentation Effect - Correct Answers -When an encased explosive such as a pipe
bomb detonates, the rapidly expanding gases produced by the explosion enlarge the
casing to about one and one-half times its original diameter before it ruptures
When it ruptures, the casing breaks into fragments that are propelled away from the
center of detonation
Primary Fragmentation - Correct Answers -Has intimate contact with explosive material
or is produced by the explosive container/device
Yields incriminating forensic evidence
Secondary Fragmentation - Correct Answers -Objects propelled from around detonation
point, and fractured pieces of the intended target that become lethal missiles
Firebrand - Correct Answers -Projected hot fragmentation, burning energetic material,
or burning debris whose thermal energy is transferred to the surroundings
IED - Correct Answers -A device placed or fabricated in a manner incorporating
destructive, lethal, noxious, pyrotechnic, or incendiary chemicals designed to kill,
destroy, incapacitate, harass, or distract
It could incorporate military, commercial, or homemade explosives, or military ordnance
but is normally devised from nonmilitary components
Four Components of IEDs - Correct Answers -Power Source
WITH CORRECT ANSWERS
Three Types of Explosions - Correct Answers -Mechanical
Chemical
Nuclear
High Explosive - Correct Answers -Explosive which normally requires a blasting cap for
initiation and once initiated produces a supersonic detonation with a shattering or
brisant effect
Detonate without confinement, doesn't need container
Low Explosive - Correct Answers -Explosive, which when unconfined, responds to
initiation by deflagration or burning and produces a pushing effect
Transitions from deflagration to detonation when confined
Incendiary Explosive - Correct Answers -Explosive designed to start fires or destroy
sensitive equipment
Detonation - Correct Answers -Supersonic combustion that propagates through shock
compression generating exothermic heat and an accompanying blast wave
Deflagration - Correct Answers -A subsonic combustion that propagates through
thermal conductivity
Effects of an Explosion - Correct Answers -Thermal
Blast Pressure
Fragmentation
Thermal Effect - Correct Answers -Usually seen as a bright flash or fireball at the
moment of detonation
May cause localized ignition of highly combustible materials
Generally least damaging of the three effects
,Blast Pressure Effect - Correct Answers -Very hot gasses (between 3,000 and 7,000
degrees Fahrenheit) expand out from the point of detonation at supersonic velocities
(up to 20,000 mph)
The further the pressure wave travels, the less power it has
Most powerful and destructive/deadly of the effects
When taking place in a confined area, it can amplify the original blast wave
Two Phases of Blast Pressure - Correct Answers -Positive Phase
Negative Phase
Positive Phase of Blast Pressure - Correct Answers -Pressure wave moving outward
from the point of detonation
Negative Phase of Blast Pressure - Correct Answers -Partial vacuum is created near
the epicenter due to the outward movement of air and the consumption of oxygen from
the combustion process
4 Types of Injuries Sustained During a Blast - Correct Answers -Primary Blast Injury
Secondary Blast Injury
Tertiary Blast Injury
Quaternary Injury
Primary Blast Injury - Correct Answers -Caused by direct effects of blast
Secondary Blast Injury - Correct Answers -Caused by propelled fragmentation (most
deadly)
Tertiary Blast Injury - Correct Answers -Occurs when a casualty's body is propelled by
the blast against the ground or stationary objects
Quaternary Injury - Correct Answers -Any other injuries (burns and crush injuries)
Three Mechanisms of Primary Blast Injury - Correct Answers -Implosion
Spalling
Inertial Effects
Implosion - Correct Answers -Occurs when blast impacts the human body by
compressing air-filled cavities in the body and causes tissue damage as compressed air
stretches, tears, and ruptures internal organs and tissues
Spalling - Correct Answers -Describes tissue injury caused when blast wave rapidly
changes velocity as it moves through tissues of different densities
, Blast Lung - Correct Answers -Severe form of pulmonary contusion, crushed lung tissue
fills with blood and cannot exhange oxygen
Inertial Effects - Correct Answers -Injury occurring when connected tissues of different
densities move at different velocities
Progressive Collapse - Correct Answers -Refers to the spread of an initial local failure
from element to element, eventually resulting in a disproportionate extent of collapse
relative to the area of initial blast damage
Two Types of Progressive Collapse - Correct Answers -Pancaking
Cascading
Pancaking - Correct Answers -Occurs when an explosion destroys a structural member
or members, causing floor directly above destroyed members to collapse and the floor
above that to collapse and so on
Cascading - Correct Answers -Collapsing of a series of bays from the destruction of one
or few bays
Fragmentation Effect - Correct Answers -When an encased explosive such as a pipe
bomb detonates, the rapidly expanding gases produced by the explosion enlarge the
casing to about one and one-half times its original diameter before it ruptures
When it ruptures, the casing breaks into fragments that are propelled away from the
center of detonation
Primary Fragmentation - Correct Answers -Has intimate contact with explosive material
or is produced by the explosive container/device
Yields incriminating forensic evidence
Secondary Fragmentation - Correct Answers -Objects propelled from around detonation
point, and fractured pieces of the intended target that become lethal missiles
Firebrand - Correct Answers -Projected hot fragmentation, burning energetic material,
or burning debris whose thermal energy is transferred to the surroundings
IED - Correct Answers -A device placed or fabricated in a manner incorporating
destructive, lethal, noxious, pyrotechnic, or incendiary chemicals designed to kill,
destroy, incapacitate, harass, or distract
It could incorporate military, commercial, or homemade explosives, or military ordnance
but is normally devised from nonmilitary components
Four Components of IEDs - Correct Answers -Power Source
