Chapter 4 Fire dynamics

Question 1

True or false?
Oxidizers are not combustible

Answer 1

True

Question 2

Energy is the capacity to perform _____?

Answer 2

Work

Question 3

Potential energy available for release in combustion process is ________

Answer 3

Heat of combustion

Question 4

What are the 4 variables that affect fuel release rates

Answer 4

-Chemical composition
-Arrangment
-Density of fuel
-Available oxygen for combustion

Question 5

What are the two measurements of heat and energy?

Answer 5

Joules and BTU

Question 6

Converting water to steam would be what kind of reaction?

Answer 6

Endothermic reaction

Question 7

True of false?
Auto-ignited temperature is always lower than a piloted ignition temperature

Answer 7

FALSE

Question 8

As the heat transfers to gaseous combustion products, they expand and do what?

Answer 8

Move up and rise away due to buoyancy

Question 9

What chemical combines with hemoglobin and excludes oxygen from being transported from the brain?

Answer 9

Carbon Monoxide

Question 10

What causes release of of Hydrogen cyanide?

Answer 10

Incomplete combustion of substances that contain nitrogen and carbon

Question 11

True or false?
Gases always move from areas of lower pressure to areas of higher pressure

Answer 11

FALSE

Question 12

True or false?
A higher heat release rate is directly correlated to higher temperature

Answer 12

False

Question 13

Multiple question on radiation, convection, conduction

Answer 13

Convection

Question 14

What is known as the reducing agent in a combustion reaction?

Answer 14

Fuel

Question 15

In vapor density, if a gas is denser than 1.0, will it rise or sink ?

Answer 15

Sink

Question 16

Explain the difference between flash point and fire point?

Answer 16

Answer

Question 17

What are the 3 key factors that control how the fire develops?

Answer 17

-Fuel properties
-Ventilation available
-Heat conservation

Question 18

Rearange the four stages of fire development:
- Growth stage
-Decay stage
-Incipient stage
-Fully developed stage

Answer 18

• Incipient
  -Growth
  -Fully developed
  -Decay

Question 19

When a fire starts to spread horizontally because of the ceiling, it is called

Answer 19

Ceiling jet

Question 20

True of false?
A decaying fire means it is safe

Answer 20

FALSEEEE

Question 21

What are the two reasons for a fire to start decaying

Answer 21

Not enough oxygen to maintain combustion and heat release has decreased to the point that fuel gases will not ignite

Question 22

Explain what a flash-over is

Answer 22

A rapid transition between growth and fully-developed has new oxygen introduced and starts up again

Question 23

If a room has a lower neutral plane and a flashover is imminent, is it because the room is fuel limited or ventilation limited?

Answer 23

Ventilation limited

Question 24

What is the difference between flash-over and backdraft?

Answer 24

Ignition because of heat rising in a ventilation limited room causing everything to combust vs explosion because a sudden intake of oxygen in a non-ventilated room

Question 25

A smoke explosion can occur when a bunch of unburned fuel gases and oxygen come in contact with….

Answer 25

An ignition source