Firefighter 2 Ch 4

Heated glass expands due to the increase in temperature. When struck by cold water, the sudden change in temperature causes the glass to contract rapidly, resulting in stress and potential cracks. This is because the glass cools down unevenly, with the outer surface cooling faster than the inner surface. The difference in temperature between the outer and inner layers creates tension, leading to the glass cracking and shattering.

The amount of smoke coming from a building is not an indicator of building collapse. While a fire may be present in a building that has collapsed, the presence or absence of smoke does not directly indicate whether a building is at risk of collapsing. Other indicators such as walls that appear to be leaning, structural members separating from walls, and structural members that appear to be distorted are more reliable signs of potential building collapse.

Placing a manned master stream device in the collapse zone is not an action to be taken when imminent building collapse is suspected. This is because a manned master stream device is typically used for firefighting purposes and is not appropriate or safe to use in a collapse zone. The priority in such a situation should be to exit the building, clear the collapse zone, and inform command and others inside the building of the situation.

Steel elongates when heated because it has a high coefficient of thermal expansion. This means that as the temperature increases, the atoms in the steel lattice vibrate more vigorously, causing the lattice to expand. This expansion leads to an increase in the length of the steel material.

Wood reacts to fire conditions based on its size and moisture content. The size of the wood determines the amount of fuel available for the fire, while the moisture content affects how easily the wood ignites and burns. Dry wood with low moisture content is more flammable and burns faster, while wet wood with high moisture content is harder to ignite and burns slower. Therefore, the size and moisture content of the wood are important factors in determining its reaction to fire.

When masonry is rapidly cooled, it undergoes a sudden change in temperature which can cause thermal stress. This stress can lead to the formation of cracks in the masonry material. As the material contracts due to rapid cooling, it becomes more brittle and prone to cracking. Therefore, the correct answer is "It cracks."

Steel fails at temperatures near or above 1,000°F (538°C). At this temperature, steel undergoes a process called thermal expansion, which causes it to weaken and lose its structural integrity. This can result in deformation, warping, or even complete failure of the steel material. Therefore, it is crucial to consider the temperature limits of steel in applications where high temperatures are involved to prevent any potential failures or accidents.

Unusual creaks and cracking noises can be an indicator of building collapse because they suggest structural instability and potential failure of the building's framework. These noises may indicate that the building's support system is compromised, possibly due to structural damage or weak foundations. Therefore, it is crucial to take these sounds seriously and evacuate the building immediately to ensure safety.

Gypsum has a high water content and absorbs a great deal of heat. Gypsum is a mineral composed of calcium sulfate dihydrate, and it has a porous structure that allows it to retain a large amount of water. When heat is applied to gypsum, the water within its structure absorbs the heat, causing the gypsum to act as a heat sink. This property makes gypsum an effective material for fire-resistant and heat-resistant applications, such as in construction materials and industrial processes.

Masonry is minimally affected by fire and exposure to high temperatures because it is a non-combustible material. Unlike wood, which easily catches fire, and steel, which can weaken and deform under high temperatures, masonry is made of materials such as brick, stone, or concrete that are highly resistant to fire. This makes masonry a durable and safe choice for construction in areas prone to fires or high-temperature environments.

Water cools structural members and reduces the risk of structural collapse. When steel is exposed to high temperatures, such as during a fire, it can weaken and lose its structural integrity. By applying water to the steel, it helps to cool it down and prevent further heat transfer, reducing the risk of collapse. This is particularly important in firefighting situations where the goal is to protect the structural integrity of a building or other structures.

Smaller wood refers to wood that has a smaller size or diameter. Smaller wood tends to have less density and is therefore easier to ignite compared to larger wood. Additionally, smaller wood also burns faster, causing it to lose its structural integrity more quickly than larger wood.

Water affects burning wood by stopping the charring process, which reduces wood's strength. When wood burns, it undergoes a process called charring, where the wood's organic material breaks down and turns into charcoal. Water acts as a coolant, preventing the wood from reaching high temperatures and stopping the charring process. This interruption in the charring process reduces the wood's strength and prevents it from burning further.

Wooden floors and ceilings increase the chances of a building collapse because wood is a combustible material that can easily catch fire and spread rapidly. In the event of a fire, the wooden floors and ceilings can weaken and collapse, leading to the overall structural failure of the building. Additionally, wood is more susceptible to moisture damage, rot, and termite infestation, which can further compromise its structural integrity and increase the risk of collapse.

Fire load refers to the maximum heat that can be produced if all the combustible materials in a given area burn. It is a measure of the potential energy release in a fire scenario. By calculating the fire load, fire safety professionals can assess the potential severity of a fire and determine appropriate fire protection measures. This includes designing fire suppression systems, establishing evacuation plans, and ensuring the structural integrity of buildings. Understanding the fire load is crucial for effective fire prevention and mitigation strategies.

Roof coverage refers to the materials and design used in constructing the roof of a building. The type of roof coverage can greatly influence the spread and intensity of a fire. Certain materials, such as flammable shingles or thatched roofs, can easily catch fire and contribute to the rapid spread of flames. Additionally, the design of the roof, such as the presence of vents or skylights, can create pathways for fire to travel and increase its intensity. Therefore, the type and design of roof coverage are important factors that can contribute to the spread and intensity of a fire.

In buildings being constructed, the lack of doors contributes to rapid fire growth because doors act as barriers that can help contain and control the spread of fire. Without doors, there is no obstruction to prevent the fire from rapidly spreading throughout the building, allowing it to quickly engulf larger areas and cause more damage.

During size-up of a building, it is crucial to observe the location of the exits. This information is essential for emergency responders to determine the best approach for evacuation and rescue operations. Knowing the location of exits helps in planning escape routes, assessing potential hazards or obstructions, and ensuring the safety of occupants during an emergency situation.

During the size-up of a building, it is important to observe various factors to assess the situation. These include the roof type, age of the building, and construction materials, as they provide valuable information about the structure's stability and potential hazards. However, the location of the exits is not typically considered during the size-up process. While knowing the exits is crucial for evacuation planning, it is not directly related to assessing the building's condition or potential risks.

Missing stairwells are not a risk at buildings being renovated. When a building is undergoing renovation, there are several potential risks involved, such as breached walls, protective features not in place, and occupants living in one section while work continues in another. However, missing stairwells are not listed as one of the risks, indicating that they are not a concern during the renovation process.