NFPA 921 Guide for Fire and Explosion
Investigations 2025/2026 Exam
1
Questions and Answers | 100% Solved
fire and energy - 🧠 ANSWER ✔✔fire is a rapid oxidation process, which is
an exothermic chemical reaction, resulting the release of heat and light
energy in varying intensities. It is important that the investigator
understands the basic concepts of energy, power, and heat flux and how
the units of measurement for each are used to describe the behavior of fire
energy - 🧠 ANSWER ✔✔energy is a property of matter that manifests an
ability to perform work, either by moving over a distance against a force or
by transferring heat. Energy can be changed in form or transferred to other
matter, but it can neither be created nor destroyed. Energy is measured in
Joules (J), calories (cal), or British thermal units (Btu).
joule - 🧠 ANSWER ✔✔the heat produced where one ampere is passed
through a resistance of one ohm for one second, or it is the work required
to move over a distance of one meter against a force of one newton
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, calorie - 🧠 ANSWER ✔✔the amount of energy required to raise the
temperature of 1 gram of water by 1 degree Celsius. A calorie is equal to
2
4.184 J
Btu - 🧠 ANSWER ✔✔the quantity of heat required to raise the temperature
of 1 lb of water 1 degree Fahrenheit at a pressure of 1 atmosphere and
temperature of 60 degrees Fahrenheit. A Btu is equal to 1055 J and 252.15
cal
Power - 🧠 ANSWER ✔✔
heat flux - 🧠 ANSWER ✔✔heat flux is a term that describes the amount of
power per unit area. A kilowatt spread over 1 m2 is approximately equal to
the radiant heal flux outdoors on a sunny day. If that same kilowatt is
concentrated using a magnifying glass and only spread over .05m2 (500
cm2), there may be sufficient energy transferred to that area to cause
ignition of combustibles. Heat flux is measured in kW/m2 or W/cm2
Fire Tetrahedron - 🧠 ANSWER ✔✔the combustion reaction can be
characterized by four components: the fuel, the oxidizing agent, the heat,
and the uninhibited chemical chain reaction. Fires can be prevented or
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
Investigations 2025/2026 Exam
1
Questions and Answers | 100% Solved
fire and energy - 🧠 ANSWER ✔✔fire is a rapid oxidation process, which is
an exothermic chemical reaction, resulting the release of heat and light
energy in varying intensities. It is important that the investigator
understands the basic concepts of energy, power, and heat flux and how
the units of measurement for each are used to describe the behavior of fire
energy - 🧠 ANSWER ✔✔energy is a property of matter that manifests an
ability to perform work, either by moving over a distance against a force or
by transferring heat. Energy can be changed in form or transferred to other
matter, but it can neither be created nor destroyed. Energy is measured in
Joules (J), calories (cal), or British thermal units (Btu).
joule - 🧠 ANSWER ✔✔the heat produced where one ampere is passed
through a resistance of one ohm for one second, or it is the work required
to move over a distance of one meter against a force of one newton
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, calorie - 🧠 ANSWER ✔✔the amount of energy required to raise the
temperature of 1 gram of water by 1 degree Celsius. A calorie is equal to
2
4.184 J
Btu - 🧠 ANSWER ✔✔the quantity of heat required to raise the temperature
of 1 lb of water 1 degree Fahrenheit at a pressure of 1 atmosphere and
temperature of 60 degrees Fahrenheit. A Btu is equal to 1055 J and 252.15
cal
Power - 🧠 ANSWER ✔✔
heat flux - 🧠 ANSWER ✔✔heat flux is a term that describes the amount of
power per unit area. A kilowatt spread over 1 m2 is approximately equal to
the radiant heal flux outdoors on a sunny day. If that same kilowatt is
concentrated using a magnifying glass and only spread over .05m2 (500
cm2), there may be sufficient energy transferred to that area to cause
ignition of combustibles. Heat flux is measured in kW/m2 or W/cm2
Fire Tetrahedron - 🧠 ANSWER ✔✔the combustion reaction can be
characterized by four components: the fuel, the oxidizing agent, the heat,
and the uninhibited chemical chain reaction. Fires can be prevented or
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
