EXAMPLE 4.3 The 440 V, 50Hz, 3-phase 4-wire main to a workshop provides power for the following loads. (a) Three 3 kW induction motors each 3-phase, 85 per cent efficient, and operat- ing at a lagging power factor of 0-9. (b) Two single-phase electric furnaces of 250 V rating each consuming 6kW at unity power factor. (©) A general lighting load of 3kW, 250 Y at unity power factor. If the lighting load is connected between one phase and neutral, while the fummaces are connected one between each of the other phases and neutral, calculate the current in each line and the neutral current at full load. (H.N.C.)
Answers
The current in each line and the neutral current at full load is as follows:Current in Red phase (L1) = 1.406 ACurrent in Yellow phase (L2) = 1.406 ACurrent in Blue phase (L3) = 20.8 ANeutral current (IN) = 48 A.
Given information in the Example 4.3 is: The 440 V, 50Hz, 3-phase 4-wire main to a workshop provides power for the following loads. Three 3 kW induction motors each 3-phase, 85% efficient, and operating at a lagging power factor of 0.9. Two single-phase electric furnaces of 250 Voltage rating each consuming 6kW at unity power factor. A general lighting load of 3kW, 250 V at unity power factor. The lighting load is connected between one phase and neutral, while the fummaces are connected one between each of the other phases and neutral.The current in each line and the neutral current at full load can be calculated as follows:For three-phase induction motor:P = 3 kW, efficiency = 85% = 0.85, Power factor (pf) = 0.9Therefore, Apparent power S = P / pf = 3 / 0.9 = 3.33 kVADue to 3-phase motor, Line power = 3 kW, so each phase power = 1 kWPhase current Iφ = (P / 3 × Vφ cos φ) = (1000 / (3 × 440 × 0.9)) = 0.81 ALine current I = √3 × Iφ = √3 × 0.81 = 1.406 ANeutral current, IN = 0For electric furnace:P = 6 kW, Power factor (pf) = 1Therefore, Apparent power S = P / pf = 6 kVADue to the single-phase motor, Phase current Iφ = (P / Vφ cos φ) = (6000 / (250 × 1)) = 24 ALine current I = IφNeutral current, IN = 24 × 2 = 48 AFor general lighting load:P = 3 kW, Power factor (pf) = 1Therefore, Apparent power S = P / pf = 3 kVADue to lighting load, Phase current Iφ = (P / Vφ cos φ) = (3000 / (250 × 1)) = 12 ALine current I = √3 × Iφ = √3 × 12 = 20.8 ANeutral current, IN = 12 A
The current in each line and the neutral current at full load is as follows:Current in Red phase (L1) = 1.406 ACurrent in Yellow phase (L2) = 1.406 ACurrent in Blue phase (L3) = 20.8 ANeutral current (IN) = 48 ATherefore, the current in each line and the neutral current at full load is as follows:Current in Red phase (L1) = 1.406 ACurrent in Yellow phase (L2) = 1.406 ACurrent in Blue phase (L3) = 20.8 ANeutral current (IN) = 48 A.
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Related Questions
cubical tank 1 meter on each edge is filled with water at 20 degrees C. A cubical pure copper block 0.46 meters on each edge with an initial temperature of 100 degrees C is quickly submerged in the water, causing an amount of water equal to the volume of the smaller cube to spill from the tank. An insulated cover is placed on the tank. The tank is adiabatic. Estimate the equilibrium temperature of the system (block + water). Be sure to state all applicable assumptions.
Answers
Answer:
final temperature = 26.5°
Explanation:
Initial volume of water is 1 x 1 x 1 = 1 \(m^{3}\)
Initial temperature of water = 20° C
Density of water = 1000 kg/\(m^{3}\)
volume of copper block = 0.46 x 0.46 x 0.46 = 0.097 \(m^{3}\)
Initial temperature of copper block = 100° C
Density of copper = 8960 kg/\(m^{3}\)
Final volume of water = 1 - 0.097 = 0.903 \(m^{3}\)
Assumptions:
since tank is adiabatic, there's no heat gain or loss through the wallsthe tank is perfectly full, leaving no room for cooling airtotal heat energy within the tank will be the summation of the heat energy of the copper and the water remaining in the tank.mass of water remaining in the tank will be density x volume = 1000 x 0.903 = 903 kg
specific heat capacity of water c = 4186 J/K-kg
heat content of water left Hw = mcT = 903 x 4186 x 20 = 75.59 Mega-joules
mass of copper will be density x volume = 8960 x 0.097 = 869.12 kg
specific heat capacity of copper is 385 J/K-kg
heat content of copper Hc = mcT = 869.12 x 385 x 100 = 33.46 Mega-joules
total heat in the system = 75.59 + 33.46 = 109.05 Mega-joules
this heat will be distributed in the entire system
heat energy of water within the system = mcT
where T is the final temperature
= 903 x 4186 x T = 3779958T
for copper, heat will be
mcT = 869.12 x 385 = 334611.2T
these component heats will sum up to the final heat of the system, i.e
3779958T + 334611.2T = 109.05 x \(10^{6}\)
4114569.2T = 109.05 x \(10^{6}\)
final temperature T = (109.05 x \(10^{6}\))/4114569.2 = 26.5°
A 50-cm x 50-cm circuit board that contains 121 square chips on one side is to be cooled by combined natural convection and radiation by mounting it on a vertical surface in a room at 25 °C. Each chip dissipates 0.18 W of power, and the emissivity of the chip surfaces is 0.7. Assuming the heat transfer from the back side of the circuit board to be negligible, and the temperature of the surrounding surfaces to be the same as the air temperature of the room, determine the surface temperature of the chips. Evaluate air properties at a film temperature of 30 °C and 1 atm pressure. Is this a good assumption?
Answers
Answer:
Ts = 311.86 K = 38.86°C
Explanation:
The convection heat transfer coefficient for vertical orientation of the board is given by the formula:
\(h = 1.42(\frac{T_{s} - T_{f} }{L})^{0.25}\)
where,
h = heat transfer coefficient
\(T_{s}\) = surface temperature
\(T_{f}\) = Temperature of fluid (air) = 30°C + 273 = 303 K
L = Characteristic Length = 50 cm = 0.5 m
Since the heat transfer through convection is given as:
\(Q_{conv} = hA_{s}(T_{s} - T_{f})\)
using value of h, we get:
\(Q_{conv} = 1.42(\frac{T_{s} - T_{f} }{L})^{0.25} A_{s} (T_{s} - T_{f} )\)
\(Q_{conv} = 1.42 A_{s} \frac{(T_{s} - T_{f} )^{1.25} }{L^{0.25} }\)
where,
\(A_{s}\) = Surface Area = (0.5 m)(0.5 m) = 0.25 m²
Now, the radiation heat transfer is given by:
\(Q_{rad} =\) εσ\(A_{s} [(T_{s})^{4} - (T_{surr})^{4}]\)
where,
ε = emissivity of surface = 0.7
σ = Stefan Boltzman Constant = 5.67 x 10⁻⁸ W/m².k⁴
\(T_{surr}\) = Temperature of surroundings = 25°C +273 = 298 k
Now, the total heat transfer rate will be:
\(Q_{total} = Q_{conv} + Q_{rad}\)
using values:
\(Q_{total} =\) \(1.42 A_{s} \frac{(T_{s} - T_{f} )^{1.25} }{L^{0.25} } +\) εσ\(A_{s} [(T_{s})^{4} - (T_{surr})^{4}]\)
we know that the total heat transfer from the board can be found out by:
\(Q_{total} = (0.18 W) (121) = 21.78 W\)
using values in the equation:
21.78 = (1.42)(0.25)\((T_{s} - 303)^{1.25}/0.5^{0.25}\) + (0.7)(5.67 x 10⁻⁸)(0.25)\([(T_{s})^{4} - 298^{4}]\)
21.78 = (0.4222)\((T_{s} - 303)^{1.25}\) + 9.922 x 10⁻⁹\((T_{s} )^{4}\) - 78.25
100.03 = (0.4222)\((T_{s} - 303)^{1.25}\)+ 9.922 x 10⁻⁹\((T_{s} )^{4}\)
Solving this equation numerically by Newton - Raphson Method (Here, any numerical method or an equation solver can be used), we get the value of Ts to be:
Ts = 311.86 K = 38.86°C
The film temperature is the average of surface temperature and surrounding temperature. Therefore,
Film Temperature = (25°C + 38.86°C)/2 = 31.93°C
Since, this is very close to 30°C.
Hence, the assumption is good.
Assume an ideal drawing process, find what is the smallest final diameter to which a 50-mm
diameter rod can be drawn? If you include friction, would the final diameter be different?
Explain.
Answers
Assuming an ideal drawing process, the smallest final diameter to which a 50-mm diameter rod can be drawn would depend on the amount of reduction in diameter desired. The reduction in diameter is typically expressed as a percentage and is determined by the difference between the initial diameter and the final diameter, divided by the initial diameter.
If the reduction in diameter desired is 50%, then the final diameter would be 25 mm. If the reduction in diameter desired is 75%, then the final diameter would be 12.5 mm.
If friction is included in the drawing process, the final diameter would be different as friction would increase the resistance to deformation, making it more difficult to draw the rod to the desired diameter. This would result in a larger final diameter than what would be achieved in an ideal drawing process without friction. The amount of increase in final diameter due to friction would depend on the coefficient of friction between the rod and the die used in the drawing process.
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The rectifier is used to
Answers
Answer:
A rectifier is an electrical device used to convert alternating current to direct current.
Explanation:
Hope this helps! Shalom
grade 5 bolts have __ identifying on the head
Answers
Grade 5 bolts have 3 marks identifying on the head
This is further explained below.
What are Grade 5 bolts?Generally, When looking for the correct bolt, it is essential to check that the grades of the bolts that are currently being used are compatible with one another.
There is no difference between Grade 5 Bolts and Metric.
8 Bolts. The presence of three marks on the head of a Grade 5 bolt is often all that is required for successfully identifying the bolt.
In conclusion, The head of a grade 5 bolt will have three distinguishing markings on it.
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data definition a type of business rule, or explanation of term or fact, a concise, singular description of what data is gathered along with systems requirements, using common words usually accompanied by diagrams (e.g., erd) achieved by consensus, and iteratively refined
Answers
A data definition is a set of agreed-upon rules and guidelines that dictate what kind of data can be defined and stored in a database.
What is data?
Data is information or facts that are used to make decisions or develop knowledge. It can be collected, stored, and analyzed to gain insights into trends and patterns. Data can take many forms, including numbers, words, images, and videos. Data can be collected from a variety of sources, such as surveys, interviews, questionnaires, experiments, transactional records, and observational data. Data can be used to measure progress, identify problems, and make predictions. It can also be used to inform decisions, develop strategies, and improve operations. Data can be used to identify opportunities and support innovation. Data-driven decision-making can help organizations make better decisions, increase efficiency, and improve performance.
It also describes the specific structure of the data elements, as well as the value ranges and formats that are acceptable. By using standardized data definitions, it helps ensure that data is entered and read in a consistent manner, improving data quality and accuracy. Data definitions are commonly used in the design of databases and other data-management systems.
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All of the following are types of stripping except? a.end terminations b. window cuts c. spiral cuts d. indent cuts
Answers
The option that is not a types of stripping is option d. indent cuts.
What are the types of cable stripping?
They are:
1. End termination
2. window cut
3. cut spiral cut
4.circumferential and longitudinal cuts
Wire Stripping is known to be a kind of act where there is the removing of the material information from any kind of cable or wire transfers, thus making it hard to identify.
Therefore, The option that is not a types of stripping is option d. indent cuts.
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The biggest advantage of sketches is that
They can be produced quickly
They communicate ideas very quickly
There is one kind of sketch for all situations
They require special equipment to be displayed
Answers
Answer:
They communicate ideas very quickly.
Explanation:
you are designing a highway to aashto guidelines on rolling terrain where the design speed will be 70 mi/hr. at one section, a 1.25% grade and a -2.25% grade must be connected with an equal-tangent vertical curve. determine the minimum length of curve that can be designed while meeting ssd requirements.
Answers
Most vertical curves in highway design are equal-tangent curves, meaning that the horizontal distance from the curve's center to its end is the same in both directions.
What is Vertical Curve?Only seldom are equal-tangent vertical curves, which are just equal-tangent curves linked to one another, employed. We shall restrict our study to the geometry of the equal-tangent parabolic curve due to its enormous popularity.
The grades of the disconnected sections of the roadway are often determined in highway planning before any calculations for vertical curves are started.
Additionally, the stopping sight distance, decision sight distance, and design speed of the route are all well defined.
Therefore, Most vertical curves in highway design are equal-tangent curves, meaning that the horizontal distance from the curve's center to its end is the same in both directions.
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A 75-hp, 850 r/min, 500-V series motor has an efficiency of 90.2 percent
when operating at rated conditions. The series field has 30 turns/pole, and
the motor parameters are:
Armature
0.1414 ohms
IP + CW
0.0412 ohms
Series
0.0189 ohms
Resistance,
The motor has a maximum safe speed of 1700 r/min. Is it safe to operate the
motor with a 10-hp shaft load? Use the magnetization curve in Figure
11.16, and show all work. Neglect changes in windage and friction
Answers
It is not safe to operate the motor with a 10-hp shaft load.
Explanation :
Solution-
First, determine the rated speed and current of the motor:
Rated speed = 850 r/min
Rated current = 500 V / (0.1414 ohms + 0.0412 ohms + 0.0189 ohms) = 30.22 A
Next, determine the speed and current for a 10-hp shaft load:
Speed = 1700 r/min
Current = 10 hp / (75 hp * 0.902) = 0.1343 A
Finally, determine whether it is safe to operate the motor with the 10-hp shaft load using the magnetization curve. we can see that the current at 1700 r/min is 0.1264 A, which is less than the current for the 10-hp shaft load (0.1343 A).
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Compute the average (root mean square) velocity (m/s) of Neon molecules at 356 Kelvins and 0.9 bars.
Answers
Answer:
V = 20.6 m/s
Explanation:
Given that the temperature of the neon molecules = 356 Kelvin
Pressure = 0.9 bar
The mass number of Neon = 21.
Using the formula below
1/2 m v^2 = (3kT)/2
Where
T = temperature = 356 k
K = Bolzmann constant
= 1.38 × 10^-23jk^-1
NA = 6.02214076×10²³ mol⁻¹
Where NA = Avogadro number
Substitute all the parameters Into the formula
1/2 × 21/NA × v^2 = (3 × k × 356)/2
1.744×10^-23V^2 = 7.3692 × 10^-21
Make V^2 the subject of formula
V^2 = (7.37×10^-21)/1.744×10^-23
V^2 = 422.55
V = sqrt( 422.55)
V = 20.55
Therefore, the average (root mean square) velocity (m/s) of Neon molecules at 356 Kelvins and 0.9 bars is 20.55 m/s
What type of system is used by a steam engine?
A steam engine uses fuel to heat water into steam which drives a turbine, thus converting heat into mechanical energy. The steam engine is a type of ______
system.
Answers
Answer:
Steampunk Mechanical
Explanation:
Your welcome
What are the indications that Cece is having problems
with her computer hardware? Check all that apply
-losing the Internet connection
-waiting for five minutes
-computer going blank
-mouse pointer freezing
-keyboard getting stuck
Answers
Answer:
-Computer going blank .
-Mouse pointer freezing.
-Keyboard getting stuck.
Explanation:
Any problems with the computer related to its hardware will consist of issues directly related to the physical components of the PC or computer. So any problem involving the physical component of the computer, then it can be termed as a hardware problem.
Based on the problems given in the option, the hardware issues will be problems with the computer, mouse, and keyboard. These form the physical parts of the computer so they will be a hardware issue.
Thus, the correct answers are the third, fourth, and fifth options.
Answer:
c d e
Explanation:
Consider the following data for 2008 in a small suburban community:
1. number of accidents: 360 fatal 10 injury 36 pdo 314
2. number of fatalities 15
3. area population: 50,000
4. registered vehicles 35,000
5. annual vmt: 12,000,000
6. average speed 30 mi/hr
compute all relevant exposure and population based accident and fatality rates for this data. compare these to national norms for the current year. (hint: use the internet to location current national norms)
Answers
Answer:
Motorcyclist Fatality and Injury Rates per Vehicle Miles Traveled, 1998-2008. 10. 9. Fatalities in School Transportation Related Crashes,. 1998-2008.
Explanation:
1. Which of these best describes a programming language?
a. A set of rules where symbols represent actions.
b. A set of spoken commands for a robot.
c. An action performed by a robot.
d.
A list of behaviors the robot already completed.
Answers
The phrase "system of rules where symbols represent actions" sums up programming languages the best.
What best describes a programming language?Symbols that represent actions are used in a computer language's set of rules. Programming languages are the set of instructions that a computer uses to carry out projects. A programming language is a vocabulary and a set of grammatical rules for telling a computer or other computing equipment to carry out particular tasks.
High-level languages such as BASIC, C, C++, COBOL, Java, FORTRAN, Ada, and Pascal are typically referred to as programming languages. instruction. The principles that specify how a language is structured are known as syntax. In computer programming, syntax refers to the rules that govern how words, punctuation, and symbols are organized in a programming language. To define algorithms or write programs to control a machine's behavior, programmers utilize programming languages.
Therefore the correct answer is option A ) A set of rules where symbols represent actions.
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The starting workpiece in steel hot rolling of plate and sheet stock is which of the following (one best answer): (a) bar stock, (b) billet, (c) bloom, (d) slab, or (e) wire stock?
Answers
The starting workpiece in steel hot rolling of plate and sheet stock is (d) slab, as it provides the most suitable form for this process.
The steel hot rolling process involves converting a starting workpiece into a thinner and longer sheet or plate stock. This process is widely used in industries such as automotive, construction, and manufacturing. The starting workpiece in steel hot rolling can vary depending on the desired final product. However, there is one best answer to the question of which starting workpiece is used for plate and sheet stock. The correct answer is (d) slab. Slabs are rectangular blocks of steel that have been casted in a mold and allowed to cool. They are then reheated and rolled into thinner sheets or plates using a hot rolling mill.
In summary, the starting workpiece for steel hot rolling of plate and sheet stock is a slab. This is an important step in the manufacturing process that allows for the creation of high-quality steel products used in various industries.
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Which two statements correctly describe a router memory type and its contents? (Choose two)
Answers
Answer:
One statement that describes a router memory type is that it is typically volatile memory, meaning that its contents are lost when the router is powered off or restarted.
Another statement is that router memory often contains the operating system and configuration files for the router.
Explanation:
Here are two statements that correctly describe a router memory type and its contents:
1. Router Memory Type: RAM (Random Access Memory)
Its Contents: RAM stores the running configuration, routing tables, and packet buffers. It is a volatile memory, which means the contents are lost when the router is powered off or restarted.
2. Router Memory Type: NVRAM (Non-Volatile Random Access Memory)
Its Contents: NVRAM stores the startup configuration, which is used when the router boots up. As a non-volatile memory, its contents are retained even when the router is powered off or restarted.
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What is computer programming
Answers
Answer:
Computer programming is where you learn and see how computers work. People do this for a living as a job, if you get really good at it you will soon be able to program/ create a computer.
Explanation:
Hope dis helps! :)
A motor car reaches a velocity of 17 m/s from rest. Draw a velocity-time graph and determine the acceleration.
Answers
The automobile initially accelerates for 5 seconds. As a result, the velocity-time graph initially slopes and then maintains a constant speed.
What is velocity of time ?Your understanding of velocity and its scientific definition are probably similar. You are aware that a big displacement over a short period of time corresponds to a large velocity, and that velocity is measured in terms of the speed of objects in terms of miles an hour or kilometres per hour. The shift in position multiplied by the distance travelled is how average velocity is calculated. Velocity and speed describe how quickly or slowly a moving object moves. We frequently encounter circumstances when we must determine which of two or more moving objects is going faster. If the two are travelling on the same route in the same direction, it is simple to determine which is quicker.
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What are the basic things you have to study in the subject, engineering?
Answers
A small electric furnace operating on 100 voltage expends 2.0 kilo watt of power. What current is in the circuit and what is the resistance of furnace and the cost of operation for 24hours at Ghana cedis 0.05kilo watt
Answers
Therefore, the current in the circuit is 20 A, the resistance of the furnace is 5 ohms, and the cost of operation for 24 hours is 2.4 cedis.
A small electric furnace operating on 100 voltage expends 2.0 kilo watt of power.
The current in the circuit can be calculated using the formula
P = VI, where P is powerV = voltage I = current.Rearranging the formula gives
I = P/V
Substituting the given values gives :
\(I = \frac{2.0 kW}{100 V} \\ = 0.2 kA = 20 kA = 20 A\\\)
The resistance of the furnace can be calculated using the formula V = IR, where
V = voltage I = current R = resistance.Rearranging the formula gives
R = V/I
Substituting the given values gives
\(R = \frac{100 V}{20 A} \\= 5 ohms\)
The cost of operation for 24 hours can be calculated by multiplying the power usage, the time, and the cost per kilowatt-hour.
This gives 2.0 kW * 24 hours * 0.05 cedis/kWh = 2.4 cedis.
2.0 kW x 24 hours x 0.05 cedis/kWh = 24 cedis
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In Female, the twenty-third pair of chromosomes is called in in
Answers
Does anyone know this
Answers
Miguel’s presentation on the Iron Age moving into the Middle Ages was detailed. He outlined the process of smelting and clarified how metals such as copper, tin, and bronze could be combined with intense heat to create strong iron. He added some images of tools that came into wide use, such as adzes and axes and even armor. Miguel left out one tool, however, that was highly important to the civilization’s progress. What might have been that tool, and why is it important?
A.
hammer, invaluable for building homes
B.
drinking vessel, essential for carrying water
C.
fencing, to create separation between properties
D.
heavy plough, which advanced food production
Answers
The heavy plough is the most important tool that Miguel left out of his presentation. The correct option is D.
The heavy plough was an important tool in the Iron Age and Middle Ages because it allowed farmers to cultivate more land and produce more food. This led to a population increase and a more prosperous society.
The other tools mentioned are also important, but they are not as essential as the heavy plough.
The hammer is useful for building homes, but it is not as important as the plough for food production. The drinking vessel is essential for carrying water, but it is not as important as the plough for advancing food production.
Fencing is useful for creating separation between properties, but it is not as important as the plough for advancing food production.
Therefore, the correct option is D.
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suppose each bulb has resistance r . with bulb c in place, bulbs b and c are in and have equivalent resistance .target 1 of 12target 2 of 12 bulb a is in with b and c, and the total resistance of the circuit is 3 of 12target 4 of 12 with bulb c removed, bulbs a and b are in blank with total resistance 5 of 12target 6 of 12 removing bulb c blank the total resistance and thus blank the current from the 7 of 12target 8 of 12 all the battery current passes through bulb a, so bulb a gets 9 of 12 bulb b no longer has to share current with bulb c, so the current through bulb b blank and bulb b gets 10 of 12target 11 of 12 with bulbs a and b in series, the brightness of bulb a has to be blank the brightness of bulb 12 of 12
Answers
In the example, we have three bulbs with of r: A, B, and C. Let's examine the conditions of the circuit step by step:
1. When bulb C is installed, bulbs B and C are connected in parallel, creating an equivalent resistance of r/2.2. Bulb A is connected in series with the parallel arrangement of bulbs B and C, and the circuit's overall resistance is 3.3. The total resistance changes to 5r when bulb C is removed, putting bulbs A and B in series.4. Removing bulb C reduces the circuit's current flow since it raises the overall resistance.5. When bulb C is taken out, the battery's current drops to 7/12 of what it was before.
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A student lives in an apartment with a floor area of 60 m2 and ceiling height of 1.8 m. The apartment has a fresh (outdoor) air exchange rate of 0.5/hr. The stove in the apartment heats by natural gas. The student cooks a meal using two gas burners that each emit carbon monoxide (CO) at a rate of 100 mg/hr. The outdoor CO concentration can be assumed to be negligible (0 ppm). The initial (time = 0) indoor CO concentration can be assumed to be 0 ppm (except for problem 4). Carbon monoxide can be considered as an inert gas, i.e., it does not stick to or react with any surfaces or other gases in air.
1. Assume that the student cooks for a long enough period of time to achieve a steady-state CO concentration in the apartment. What is that concentration in ppb?
2. Assume that the student cooks for only 45 minutes and turns off both burners at that time. What is the CO concentration in ppb at the end of 45 minutes?
3. Repeat problem 2 for air exchange rates that vary from 0.1 to 1/hr and plot the concentration at 45 minutes (in ppb) versus air exchange rate.
4. Assume that for the conditions of problem 2, the student waits 25 minutes after turning the burners off and then starts cooking again with two burners on. How long will it take to reach a concentration that is 95% of steady-state under this condition?
Note that you can actually address this question with an eloquent mathematical derivation (preferred) or simply by crunching the concentration profile in a spreadsheet.
What is the concentration at 95% of steady-state?
Compare your result with the time that would be required to reach 95% of steady-state had the initial indoor CO concentration been 0 ppm.
Answers
Answer:
4
Explanation:
The study of control processes in systems, particularly the analysis of the flow of information in closed systems, is known as?
Answers
The study of control processes in systems and the analysis of the flow of information in closed systems is known as cybernetics.
Cybernetics is an interdisciplinary field that encompasses the study of feedback, control, and communication within systems. It focuses on understanding how information flows and influences the behavior and dynamics of complex systems. Cybernetics explores the principles and mechanisms of control and regulation in various domains, including engineering, biology, social systems, and information processing.
The term "cybernetics" was coined by mathematician Norbert Wiener in the 1940s, derived from the Greek word "kybernetes" meaning "steersman" or "governor." Cybernetics provides a framework for analyzing and designing systems that exhibit self-regulation, adaptation, and feedback loops. It has applications in fields such as robotics, control systems, artificial intelligence, and organizational management. By studying the flow of information within closed systems, cybernetics aims to understand and improve the control and behavior of these systems.
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Use the HELPrct data from the mosaicData to calculate the mean of all numeric variables (be sure to exclude missing values)
Answers
To calculate the mean of all numeric variables in the HELPrct data from the mosaicData package, we can use the colMeans() function in R. This function calculates the mean of each column in a data frame.
However, it only works on numeric columns, so we need to first remove any non-numeric columns or missing values.
To do this, we can use the select_if() function from the dplyr package to only select columns that are numeric. Then, we can use the na.omit() function to remove any rows with missing values. Finally, we can use the colMeans() function to calculate the mean of each column.
Here's the code:
library(mosaicData)
library(dplyr)
# Select only numeric columns
numeric_cols <- select_if(HELPrct, is.numeric)
# Remove rows with missing values
numeric_cols <- na.omit(numeric_cols)
# Calculate column means
means <- colMeans(numeric_cols)
# Print the result
print(means)
This will give us the mean of each numeric column in the HELPrct data, excluding any missing values.
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a pediatrician would use this instrument for viewing the interior of the eye
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A pediatrician would use an ophthalmoscope for viewing the interior of the eyes.
Ophthalmoscope is an instrument used by pediatricians and other physicians to examine the interior of the eye.
The ophthalmoscope, an important diagnostic tool in ophthalmology, enables doctors to view the retina, optic disc, macula, and other parts of the eye in detail.
The ophthalmoscope is designed to allow physicians to view the interior of the eye through the pupil. With the help of an ophthalmoscope, doctors can diagnose and monitor a variety of eye disorders, such as glaucoma, cataracts, and macular degeneration.
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A pediatrician is a doctor who specializes in treating babies, toddlers, and children up to the age of 18. Pediatricians are well-equipped to diagnose, treat, and illnesses. Because they deal with such young patients, pediatricians must have access to a variety of specialized medical instruments,
One such instrument is an ophthalmoscope. An ophthalmoscope is a handheld instrument that is used to view the interior of the eye. It allows doctors to examine the retina, optic disc, and other structures of the eye to identify any signs of damage or disease.
Pediatricians might use an ophthalmoscope to diagnose a variety of eye conditions in children. For example, they might use it to look for signs of strabismus (a misalignment of the eyes), cataracts (cloudy areas on the lens of the eye), or glaucoma (increased pressure in the eye that can damage the optic nerve)
In addition to an ophthalmoscope, they might also use other specialized instruments to examine different parts of the eye.
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Which three items below should a driver be able to identify under the hood of a car?
Answers
Answer:
Engine oil level.
Brake fluid.
Power steering fluid.