Download S-290 FINAL EXAM 2024 WITH ACTUAL CORRECT QUESTIONS AND VERIFIED DETAILED ANSWERS |FREQU and more Exams Nursing in PDF only on Docsity! 1 | P a g e S-290 FINAL EXAM 2024 WITH ACTUAL CORRECT QUESTIONS AND VERIFIED DETAILED ANSWERS |FREQUENTLY TESTED QUESTIONS AND SOLUTIONS |ALREADY GRADED A+|NEWEST|GUARANTEED PASS |LATEST UPDATE What is the general effect of stable air on wild land fires? Fire activity decreases What is the general effect of stable air on wild land fires? Fire activity decreases What conditions will occur under a surface inversion during the morning hours? All of the above Temperatures are cool, winds are calm or light Fire activity is decreased Pollutants can accumulate under inversions What conditions will occur under a surface inversion during the morning hours? All of the above Temperatures are cool, winds are calm or light Fire activity is decreased Pollutants can accumulate under inversions What are the different lighting processes that can lead to thunderstorm development? Frontal, orographic, thermal, convergence What are the different lighting processes that can lead to thunderstorm development? Frontal, orographic, thermal, convergence T/F Unstable air can often be found in low pressure systems and on the leading edge of cold fronts. True T/F Unstable air can often be found in low pressure systems and on the leading edge of cold fronts. True T/F Unstable air can be formed by either heating the air near the ground or by cooling the air aloft. 2 | P a g e True T/F Unstable air can be formed by either heating the air near the ground or by cooling the air aloft. True Wind direction is: The direction the wind is blowing from. Wind direction is: The direction the wind is blowing from. A wind is caused by: The direction the wind is blowing from. A wind is caused by: The direction the wind is blowing from. A slope wind is caused by: Warm air rising and cold air settling. A slope wind is caused by: Warm air rising and cold air settling. Foehn winds can adversely affect wild land fires because they can produce: Strong winds, warmer temperatures, and very low RH. Foehn winds can adversely affect wild land fires because they can produce: Strong winds, warmer temperatures, and very low RH. When stable air is forced over a mountain range, and then descends the leeward slopes as dry, warmed air, it is called: A foehn wind When stable air is forced over a mountain range, and then descends the leeward slopes as dry, warmed air, it is called: A foehn wind T/F Bends in canyons are likely places for wind eddies to form. True T/F Bends in canyons are likely places for wind eddies to form. True 5 | P a g e Fuel size and shape definition: The surface-area-to-flume ratio. Fuel chemical content definition: The presence of volatile substances in a fuel. Fuel chemical content definition: The presence of volatile substances in a fuel. Which of the following fuel characteristics affect all 6 wild land fire behavior concerns; i.e. ignition, spread, intensity, spotting, torching, and crowning. Moisture content Which of the following fuel characteristics affect all 6 wild land fire behavior concerns; i.e. ignition, spread, intensity, spotting, torching, and crowning. Moisture content Which fuel has the higher surface-area-to-volume ration? Grass Which fuel has the higher surface-area-to-volume ration? Grass The 1 hour timelag fuel category is: 0.0 to 1/4 inch in diameter The 1 hour timelag fuel category is: 0.0 to 1/4 inch in diameter Fuel moisture timelag can best be described as: The rate at which dead fuel gains or loses moisture. Fuel moisture timelag can best be described as: The rate at which dead fuel gains or loses moisture. 1 hour timelag fuel moisture is used in fire behavior calculations to determine: Whether fine dead fuels are available for ignition and fire spread. 1 hour timelag fuel moisture is used in fire behavior calculations to determine: Whether fine dead fuels are available for ignition and fire spread. The five stages of vegetative development for live fuel moisture are: 6 | P a g e 300%, 200%, 100%, 50%, less 30% The five stages of vegetative development for live fuel moisture are: 300%, 200%, 100%, 50%, less 30% The following statement best describes timelag fuel categories: 1 hour timelag fuels react to changes in RH mush faster than 100 hour fuels. The following statement best describes timelag fuel categories: 1 hour timelag fuels react to changes in RH mush faster than 100 hour fuels. T/F Foehn winds always cause fuels to gain in moisture content. False T/F Foehn winds always cause fuels to gain in moisture content. False T/F Dead grass reacts like a 1 hour timelag fuel. True T/F Dead grass reacts like a 1 hour timelag fuel. True The fuel moisture at which fire will not spread is the: Moisture of extinction The fuel moisture at which fire will not spread is the: Moisture of extinction Inputs used to determine fine dead fuel moisture content are: Time of day, month of year, dry bulb temperature, RH, aspect, percent slope, shading of surface fuels. Inputs used to determine fine dead fuel moisture content are: Time of day, month of year, dry bulb temperature, RH, aspect, percent slope, shading of surface fuels. Select the fuel complex that would reach it's moisture of extinction first during nighttime humidity recovery. Cured cheatgrass Select the fuel complex that would reach it's moisture of extinction first during nighttime humidity recovery. Cured cheatgrass 7 | P a g e If the wet build is not read at it's lowest point, what will happen? The calculated RH will be too high. If the wet build is not read at it's lowest point, what will happen? The calculated RH will be too high. What weather processes can and should be monitored visually? All of the above Thunderstorm buildups Clouds Approaching cold fronts Indications of a stable or unstable air What weather processes can and should be monitored visually? All of the above Thunderstorm buildups Clouds Approaching cold fronts Indications of a stable or unstable air When a cold front or thunderstorms are forecast in the vicinity of a fire, what is the most important information a security weather watch can provide? Strong shifting winds When a cold front or thunderstorms are forecast in the vicinity of a fire, what is the most important information a security weather watch can provide? Strong shifting winds The criteria for determining a Red Flag Warning is a combination of high to extreme fire danger and a critical fire weather pattern such as: All of the above Dry lightning Lightning following an extremely dry period Unusually low RH Very dry and unstable air The criteria for determining a Red Flag Warning is a combination of high to extreme fire danger and a critical fire weather pattern such as: All of the above Dry lightning Lightning following an extremely dry period Unusually low RH Very dry and unstable air 10 | P a g e 4 factors that are responsible for the occurrence of fire behavior in the third dimension are: Available fuels, wind, low atmospheric moisture, and instability. 4 factors that are responsible for the occurrence of fire behavior in the third dimension are: Available fuels, wind, low atmospheric moisture, and instability. Three stages of crown fire development are: Passive, active, and independent. Three stages of crown fire development are: Passive, active, and independent. T/F Crown fire development depends on crown flammability along with adequate surface-to-crown and crown-to-crown heat transfer. True T/F Crown fire development depends on crown flammability along with adequate surface-to-crown and crown-to-crown heat transfer. True The factors that contribute to the spotting problem can be classified into three general areas: Firebrand source, transportation, and the receiving fuel. The factors that contribute to the spotting problem can be classified into three general areas: Firebrand source, transportation, and the receiving fuel. Probability of ignition is determined by: Fuel shading, fine dead fuel moisture percent, and dry bulb temperature. Probability of ignition is determined by: Fuel shading, fine dead fuel moisture percent, and dry bulb temperature. T/F Vortices are grouped as vertical or horizontal depending on their axis of rotation. True T/F Vortices are grouped as vertical or horizontal depending on their axis of rotation. True When the wild land fire environment is dominated by a ______ fire, the convection column overpowers the wind field. Plume-dominated 11 | P a g e When the wild land fire environment is dominated by a ______ fire, the convection column overpowers the wind field. Plume-dominated T/F Continous fine fuels, heavy fuel loadings, ladder fuels, crown spacing, and special fuel situations are fuel characteristics that should NOT be monitored. False T/F Continous fine fuels, heavy fuel loadings, ladder fuels, crown spacing, and special fuel situations are fuel characteristics that should NOT be monitored. False Low RH and a high 1000 hour timelag fuel moisture are both critical fuel moisture indicators that should be monitored. False Low RH and a high 1000 hour timelag fuel moisture are both critical fuel moisture indicators that should be monitored. False T/F Steep slopes, chutes, saddles, and narrow canyons are terrain indicators that should be monitored. True T/F Steep slopes, chutes, saddles, and narrow canyons are terrain indicators that should be monitored. True T/F Strong surface winds, lenticular clouds, high fast moving clouds, approaching cold front, cumulonimbus development, and sudden calm or battling winds are all indicators of wind that are not of great concern to wild land firefighters. False T/F Strong surface winds, lenticular clouds, high fast moving clouds, approaching cold front, cumulonimbus development, and sudden calm or battling winds are all indicators of wind that are not of great concern to wild land firefighters. False Which of the following is an indicator of stable air? Inversion Which of the following is an indicator of stable air? Inversion Which is an indicator of possible fire behavior problems? 12 | P a g e All of the above Leaning, sheared, or well-developed smoke column Trees crowning Fire whirls beginning Frequent spot fires Which is an indicator of possible fire behavior problems? All of the above Leaning, sheared, or well-developed smoke column Trees crowning Fire whirls beginning Frequent spot fires T/F Topography can directly and indirectly affect fuels and their availability for combustion. True T/F Topography can directly and indirectly affect fuels and their availability for combustion. True Of the three primary environmental factors that influence fire behavior, which is the least variable? Topography Of the three primary environmental factors that influence fire behavior, which is the least variable? Topography The least critical form of heat transfer that influences rate of spread in a running wild land fire is: Conduction The least critical form of heat transfer that influences rate of spread in a running wild land fire is: Conduction The point to which a combustible material must be heated to produce self-sustaining combustion is known as the: Ignition temperature The point to which a combustible material must be heated to produce self-sustaining combustion is known as the: Ignition temperature Fireline intensity is dependent upon: All of the above. Fuel size Fuel moisture 15 | P a g e T/F The type of vegetation has little affect on temperature and humidity. False T/F RH measures the amount of moisture in the air. True T/F RH measures the amount of moisture in the air. True S/U Clouds form in layers. Stable S/U Clouds form in layers. Stable S/U Gusty winds Unstable S/U Gusty winds Unstable S/U Smoke column spreads out after limited rise. Stable S/U Smoke column spreads out after limited rise. Stable S/U Clouds grow vertically Unstable S/U Clouds grow vertically Unstable S/U Firebrands are lifted into convection column. Unstable S/U Firebrands are lifted into convection column. Unstable T/F Temperature decreases with an increase in elevation when an inversion is present. False T/F Temperature decreases with an increase in elevation when an inversion is present. 16 | P a g e False List 3 methods of mass transport of firebrands on wild land fires? Conduction, wind, and gravity In an instable atmosphere: Smoke will continue to rise as long as it remains warmer than the surrounding atmosphere and air parcels both rise and sink Describe how convection influences transport of firebrands Rising heat produced from fires can lift firebrands within the column. These firebrands can then be deposited ahead of the fire as they fall out of the column. The primary factors that affect rate of spread are: Changes in fuel type, wind speed, and steepness of slope. Which of the following changes would be expected to produce the largest change in ROS? A slope reversal with a 6 mph wind blowing at one slope The 4 fuel factors that affect the ignition of wild land fires are: Size and shape of fuels, compactness or arrangement of fuels, fuel moisture, and fuel temperature. Define fuel moisture content: The amount of water in fuel expressed as a percent of the oven dry weight of that fuel. The fire weather planning forecast, spot forecasts, red flag warnings, and smoke management forecasts are products issued by: The National Weather Service Which one or more of the following statements are correct regarding wind driven and plume dominated fires: Wind driven fires are easier to predict the direction of spread Plume dominated fires have similar hazards to thunderstorms Plume dominated fires the convected column dictates the fire activity List the 3 methods used in the field to determine slope percent: Clinometer/abney, measurement using a stick propped into slope and percent slope formula, slope meter estimate Upslope winds are typically weakest on what aspect: North The 3 stages of crown fire development include: 17 | P a g e Passive, active, and dependent Slope effects fuel availability to burn because: Fuels are preheated upslope through radiation and convection Rolling firebrands ignite fuels below Which of the following topographic variations in wind speed would expect on a sunny summer afternoon: Highest wind speeds on upper windward slopes Lowest wind speeds on downwind slopes Inputs used to determine fine dead fuel moisture content are: Time of day, month of year, dry bulb temp, RH, aspect, percent slope, and shading of surface fuels General winds are: Large scale winds caused by the pressure gradients associated with highs and lows. If the wet bulb is not read at it's lowest point on a psychrometer The calculated Rh would be too high Branches above the fire are receiving heat by: Radiation and convection RH is: The ratio of the amount of water vapor in the air to the amount of water vapor the air can hold when saturated at the same temperature. Select the correct statement regarding the shape of the country and it's effect on wild land fire behavior: The shape of the country can influence the curing of the fuels as well as the intensity and spread of fires. Select the statement that best describes the affect of slope on fuels: A fire starting at the base of a slope has more fuel available for spread Fuel beds on S and SW aspects are usually drier Of the 3 methods for obtaining live fuel moistures, the following produces the most accurate results: Collecting samples, weighing them, drying them and then weighing them again. List in order the 3 main fuel types from slowest to fastest rate of spread: Litter, crown, grass 7 day significant fire potential, monthly fire weather/fire danger outlooks, and seasonal assessments, are all products produced by what organization. 20 | P a g e Name the 5 weather factors that effect fire behavior. (WARPT) Windspeed and direction Atmospheric stability Relative Humidity Precipitation Temperature Name the 5 topographic factors that affect fire behavior Elevation Position on slope Aspect Shape of the country Steepness of slope Name the 7 fuel factors that effect fire behavior Fuel loading Size and shape Compactness Horizontal continuity Vertical continuity Chemical content Fuel moisture and Fuel temperature Which of the three components of fire enviornment, changes most rapidly over time and space? Weather Which of the three components of the fire enviornment is the least variable? Topography Which fuel characteristics vary rapidly over time and space? Fuel moisture and Fuel temperature The form of heat transfer that has the most influence on the rate of spread in a ground fire is... Conduction These fires are difficult to extinguish and have smoldering or creeping fire behavior Ground Fires What form of heat transfer has the most influence on rate of spread in a backing fire? Radiation 3 ways convection energy can spread a fire 21 | P a g e 1. Cause spot fires 2. Preheat fuels through air and increased direct flame contact 3. Increase the amount of oxygen introduced on a fire What form of heat transfer has the most influence on tree limbs Convection List three forms of mass transport of firebrands on wildland fires 1. Convection 2. Wind 3. Gravity Give 3 examples of fire brands affected by gravity 1. pine cones 2. yuccas 3. logs Three requirements for long range spotting 1. Strong convective influence to create fire brands 2. High winds to spread the fire brands 3. A receptive fuel bed Define Flamelength The distant measured from the tip of the flame to the middle of the flaming zone at base of fire. Where do fire behavior predictions describe the average flame length? Head of the fire/flamefront Flame length is a visual indicator of Fireline intensity/ BTU per foot per second 6 Primary fuel factors that affect ignition of a wildland fire 1. moisture 2. size and 3. shape 4. arrangement 5. compactness 6. temperature BTU per foot per second, rate of energy release, indicated by flame length, and represents the ead output at the flame front is.... Fireline Inensity A chain is 22 | P a g e 66 feet 1 Mile equals how many chains 80 chains How many square chains in an acre 10 sq. chains Fireline intensity is affected by... 1. Fuel loading 2. Compaction 3. Arrangement 4. Fuel moisture 5. Rate of spread The factors that affect rate of spread are... 1. Changes in fuel type 2. wind speed 3. steepness of slope A surface fire that has a head and is spreading with the wind or slope is called Running fire You observed a convection column bend over as it rises, list 2 fire behavior concerns 1. Spot fire potential 2. High winds aloft can surface and create wind shifts What 3 things can convection from a fire do 1. Create cumulus clouds 2. Change wind direction 3. Affects stability Humid climates usually have __________ temperatures during the night than do dry climates Higher About half of the weight of the atmoshere is below________ 18,000 feet Nearly all the weather in the atmosphere occurs in the_________ Troposphere Water vapor is in the greatest percentage in which region? The tropics 25 | P a g e What is identical to the wet bulb temperature when the air is saturated and also the temperature that we would expect fog or clouds to form? Dew Point Temperature Nearly all weather occurs within the __________ Troposphere The two instruments used to measure atmospheric pressure 1. Aneroid barometer 2. Mercury barometer Nearly half the weight or mass of the atmosphere is concentrated __________ In the lowest 18,000 feet of the atmosphere On average, air pressure ________ approximately _________ every 1000 foot increase in elevation within the lowest 10,000 feet of the atmosphere Decreases; 1 inch of mercury Why do dry climates usually have greater temperature differences between night and day than humid climates? There is less water vapor in the air to hold in heat at night and reflect radiation during the day What has a lower albedo, dark soil or a snow covered field? Dark Soil What substances has the highest specific heat capacity? Water How does evaporation affect the atmosphere It cools and moistens it This accounts for small daily and seasonal temperature variations in high humidity regions The greenhouse effect Based on the normal daily temperature lag, when will the highest daytime temperature most likely occur during summer? 3 p.m. The degree of hotness or coldness of a substance Temperature The lowest temperature to which air can be cooled by evaporation 26 | P a g e Wet Bulb The temperature to which air must be cooled to reach saturation. Dew point Stronger winds at night will Keep temperatures warmer and relative humidity low A slope wind is caused by warm air ________ and cold air _________. Warm = Rising Cold = settling How do Foehn winds affect wind, temperature, and relative humidity? 1. Create Strong Winds 2. Bring warmer temperatures 3. Bring very low relative humidity When stable air is forced over a mountain range, and then descends the leeward slopes as dry, warmed air, it is called a _________ Foehn Wind True/ False Bends in canyons are likely places for gusty and sudden wind eddies to form True Small scale winds caused by differences in pressure created by heating and cooling Local Winds Sundowner, East, Mono, Santa Ana, and Chinook are all examples of _________ Foehn winds Which way does air flow in a Low pressure system Air flows counterclockwise and rises Which way does air flow in a High Pressure system Air flows clockwise and sinks Up-slope winds are weakest on what aspect North Lowest wind speeds on downwind slopes and highest wind speeds on upper windward slopes are wind variations you would expect when? Sunny summer afternoons 27 | P a g e Large-scale winds caused by pressure gradients between highs and lows General Winds Common general winds associated with passage of cold fronts are.... 1. Southeast switching to the southwest becoming very gusty then switching to a very strong Northwest wind 2. 90 to 180 degrees shift clockwise with increasing strong gusty winds The stronger the pressure gradient the _______the winds. Stronger Do winds flow from Low to High pressure systems or from High to low pressure systems? High to low pressure Daytime winds Up-slope 3-8 mph Up canyon/valley 10-15 mph Nighttime winds Down-slope 2-5 mph Down canyon/valley 5-10 mph Daytime coastal winds Sea-breeze onshore 10-20 mph Nighttime coastal winds Land breeze offshore 3-10 mph How strong are thunderstorm in-drafts 10-20 mph How strong are thunderstorm downdrafts? 25-35 mph with gusts 60+ How strong are Foehn winds Down-slope 40-60 mph + When are Santa Ana Foehn winds expected to surface and from what direction? From the Northeast to East and during the night When will Santa Ana's battle an onshore wind? 30 | P a g e +/- 3.5 degrees Fahrenheit Will adding water vapor to an air parcel make it lighter or heavier lighter; moist air is lighter than dry air A column of cold, dry air is ______(lighter, heavier) and generally more _______(stable, unstable) than a column of warm, humid air. Heavier and stable Haines Index measure what two things? Stability and dryness Define Convergence: The coming together of two air masses Lifting produced when two air masses converge Frontal Air that is forced to rise as it is pushed against mountainous terrain Orographic Strong lifting produced by diverging winds and low air pressure aloft Jet Stream The rising of air currents as a result of surface heating Thermal lifting Which lifting process can cause explosive growth in smoke columns and thunderstorms? Jet Stream True/ False A thunderstorm is ALWAYS accompanied by lightening and thunder? True What 3 things are required to produce a thunderstorm? 1. Lifting mechanism 2. favorable instability 3. adequate moisture What are the 3 stages of thunderstorms 1. cumulus (updraft stage) 2. Mature (updraft and downdraft stage) 3. Dissipating (downdraft stage) 31 | P a g e The spreading out top of a cumulonimbus or thunderstorm cloud is called An Anvil The wind speed that affects a surface fire (roughly at eye level) that is used in the fire behavior spread calculations Mid-Flame Wind Winds caused by strong pressure gradients in the boundary area of two dissimilar air masses; characterized by shifting winds and increased velocities Frontal Wind Large scale winds caused by the pressure gradients associated with highs and lows General wind The wind measured at the 20- foot level Surface wind These clouds are an indication of a significant weather change in the next 2-3 days Cirrostratus These clouds are a major concern to firefighters because of the potential for strong, gusty and erratic winds. Cumulonimbus These clouds are formed with turrets and is an indicator of very unstable air at middle levels of the troposphere. Altocumulus castellanus These clouds are an indicator of stable air at middle levels of the troposphere, and it is often associated with gusty winds in the lee of mountain ranges. Altocumulus lenticularus These clouds are scattered tufts with rounded and slightly bulging upper parts. Altocumulous folccus These clouds are an indication of stable and often moist air near the ground Stratus