Driver/ Operator Pumper (USAF) Questions and Answers 100% Solved

Driver/ Operator Pumper (USAF) Questions and Answers 100% Solved Water ✔️✔️- most commonly used extinguishing agent - noncombustible - absorbs large amounts of heat Waters Boiling Point ✔️✔️212° F Waters freezing point ✔️✔️32°F Waters Expansion Rate ✔️✔️1,700 to 1 at 500° F Law of Specific Heat ✔️✔️Measures the ability of any substance to absorb heat Measured in BTUs (British Thermal Units) 1 BTU = the amount of heat required to raise 1lb of water 1°F Law of Latent Heat of Vaporization ✔️✔️The amount of heat needed to turn a liquid into a vapor 1 BTU to raise 1lb of water 1 degree up to 212° F Adjustable Fog Nozzle ✔️✔️Straight Stream Narrow Fog Wide Fog All 3 discharge at a rate of 100 gpm The wider the pattern, the shorter the time span to fill a room with steam. Advantages of Water ✔️✔️1. Can absorb large amounts of heat 2. As surface area increases, heat absorption increases 3. Water is plentiful in most areas 4. Steam occupies 1,700 times its original volume as water Disadvantages of Water ✔️✔️1. High surface tension limits its penetration into dense materials 2. Incompatible with or reactive to certain fuels and combustible materials 3. Ice makes roofs and ladders slippery and can make equipment malfunction 4. Conducts electricity and makes work with energized electrical equipment dangerous Water Pressure ✔️✔️The force of water per unit area PSI ✔️✔️pounds per square inch The elevation of water defines psi Column of water = 1 in x 1 in x 12 in = 0.434 psi Height determines psi 6 Characteristics of Water ✔️✔️BED PAD Bottom Equal Depth Perpendicular All Density Bottom ✔️✔️The pressure at the bottom is independent of the shape of the liquid container above it Equal ✔️✔️The pressure transmitted to a confirmed amount of water is transmitted equally in all directions Depth ✔️✔️The pressure of water in an open container is proportional to its depth Perpendicular ✔️✔️The pressure on an amount of water is perpendicular to any surface it acts on All ✔️✔️At any point in the water in a container, pressure is equal in ALL directions - including upwards Density ✔️✔️The pressure of a liquid in an open container is proportional to the density of the liquid Density = the materials weight compared to that of an equal quantity of water 6 Types of Pressure ✔️✔️1. Atmospheric 2. Head 3. Static 4. Flow 5. Residual 6. Normal operating