Chapter 5 - Principles of Water Flashcards
The ______ must understand factors that influence water supply ______ and how the availability of water for fire suppression is achieved using a variety of ______.
- driver/operator
- capability
- methods
What is the most common weapon in the FF’s arsenal?
water
You must understand why water is an effective WHAT and the physics of WHAT kind of water?
- extinguishing agent
- moving
Below 32 degrees F (0C), water becomes a solid called?
ice
Above 212 degrees F (100C) is called the WHAT of water? it converts to what? (3)
- boiling point
- gas, water vapor or steam
You can see water vapor? TRUE or FALSE
FALSE
When can you start to see water vapor?
when it rises away from the surface of liquid and begins to CONDENSE
Water is considered virtually incompressible? TRUE or FALSE
true
Does waters weight vary with temperature? YES OR NO
YES
Water’s density (weight per unit of volume) is measured in WHAT per cubic foot?
pounds
For fire protection, fresh water is considered to weigh ____lb/ft3 or ____ lb/gal.
- 62.4
- 8.3
When water smothers a fire, it does this?
excludes oxygen
Can water heat or contribute heat to a fire?
No, it cools and absorbs
What kind of combustible liquid can water smother?
those with a specific gravity greater than 1
What is the specific gravity of water?
1
Within a closed space, how might water smother a fire?
when it converts to steam
Does gas have a higher or lower specific gravity than water?
lower, .72-.76
Does Methylene Chloride have a higher or lower specific gravity than water?
higher, 1.33
Pressure in this manual means force per unit area or?
pounds per square foot/pounds per square inch
What is pressure confused with?
force
Force is a simple measure of WHAT?
weight
Force is measured in WHAT?
pounds or newtons or kilograms
What force is “force” directly related to?
the force of gravity, the amount of attraction the earth has for all bodies
If several objects are placed on a flat surface and are all the same size and weight, they exert the same WHAT on that surface?
force