CFI Fire Dynamics & Behavior Flashcards
6 cards from real CFI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CFI Fire Dynamics & Behavior flashcards as text
What does 'area of origin' mean in fire investigation terminology?
Answer: The room, area, or space within which the fire originated
The area of origin is the room, area, or space within which the fire originated, which may be further narrowed to a point of origin.
The 'thermal inertia' of a material is a measure of its:
Answer: Resistance to changes in surface temperature due to thermal conductivity, density, and specific heat
Thermal inertia (kρc) combines thermal conductivity, density, and specific heat to describe how quickly a material's surface temperature responds to heat flux.
When investigating a fire, 'burn indicators' on structural elements are analyzed using which primary methodology recommended by NFPA 921?
Answer: The scientific method
NFPA 921 mandates the use of the scientific method — observation, hypothesis, testing, and conclusion — as the systematic approach for analyzing all fire evidence including burn indicators.
Which phenomenon explains why charring can sometimes be found low on walls even without accelerant use?
Answer: Flashover causes uniform room involvement that burns low on walls
Post-flashover conditions create high radiant heat from all surfaces that can char wall areas at low levels, mimicking pour patterns and making origin determination more complex.
What is the primary significance of 'alligatoring' (large blisters) versus 'small alligatoring' on charred wood surfaces?
Answer: Large alligatoring may indicate rapid, intense burning; small alligatoring may indicate slower burning
While not definitive proof of accelerant use, large shiny alligatoring can suggest rapid, intense heat exposure, whereas small dull alligatoring may indicate slower, longer burning.
In fire dynamics, 'flame height' is primarily a function of which fire variable?
Answer: Heat release rate
Flame height is primarily determined by heat release rate; as the HRR increases, flame height increases in a predictable, mathematically describable relationship.