A well-insulated heat exchanger has one line with 2 kg/s of air at 125 kPa and 1000 K entering, and leaving at 100 kPa and 400 K. The other line has 0.5 kg/s water entering at 200 kPa and 20 °C, and leaving at 200 kPa. Calculate the exit temperature of the water and the total rate of entropy generation?
Answer:
120°CExplanation:
Step one:
given data
T_{wi} = 20^{\circ}C
T_{Ai}=1000K
T_{Ae}= 400kPa
P_{Wi}=200kPa
P_{Ai}=125kPa
P_{We}=200kPa
P_{Ae}=100kPa
m_A=2kg/s
m_W=0.5kg/s
We know that the energy equation is
[tex]m_Ah_{Ai}+m_Wh_W=m_Ah_{Ae}+m_Wh_{We}[/tex]
making [tex]h_{We}[/tex] the subject of formula we have
[tex]h_{We}=h_{Wi}+\frac{m_A}{mW}(h_A-h_{Ae})[/tex]
from the saturated water table B.1.1 , corresponding to [tex]T_{wi}= 20c[/tex]
[tex]h_{Wi}=83.94kJ/kg[/tex]
from the ideal gas properties of air table B.7.1 , corresponding to T=1000K
the enthalpy is:
[tex]h_{Ai}=1046.22kJ/kg[/tex]
from the ideal gas properties of air table B.7.1 corresponding to T=400K
[tex]h_{Ae}=401.30kJ/kg[/tex]
Step two:
substituting into the equation we have
[tex]h_{We}=h_{Wi}+\frac{m_A}{mW}(h_A-h_{Ae})[/tex]
[tex]h_{We}=83.94+\frac{2}{0.5}(2046.22-401.30)\\\\h_{We}=2663.62kJ/kg[/tex]
from saturated water table B.1.2 at [tex]P_{We}=200kPa[/tex] we can obtain the specific enthalpy:
[tex]h_g=2706.63kJ/kg[/tex]
we can see that [tex]h_g>h_{Wi}[/tex], hence there are two phases
from saturated water table B.1.2 at [tex]P_{We}=200kPa[/tex]
[tex]T_{We}=120 ^{\circ} C[/tex]
How to connect the wind turbines to the grid? Give advantages and disadvantages to your answer.
Answer:
Electricity from the wind turbine generator travels to a transmission substation where it is converted into extremely high voltage, between 155,000 and 765,000 volts, for long distance transmission on the transmission grid. This grid comprises a series of power lines that connect the power sources to demand centers.The advantages of wind energy are more apparent than the disadvantages. The main advantages include an unlimited, free, renewable resource (the wind itself), economic value, maintenance cost, and placement of wind harvesting facilities.
True or false Osha engineering controls are the last strategy of control an employer should use for job hazards
Answer:
false
Explanation:
Select four items that an industrial engineer must obtain in order to practice in the field.
Answer:
agriculture,defense,industry,science
Explanation:
Edg 2021
A flexible rectangular area measures 2.5 m X 5.0 m in plan. It supports an external load of 150 kN/m^2. Determine the vertical stress increase due to the load at a depth of 6.25 m below the corner of the footing.
Answer:
19.0476 kN/m^2
Explanation:
Given data:
Dimension of rectangular area = 2.5m x 5.0m
external load = 150 KN/m^2
load depth = 6.25 m
calculate the vertical stress increase due to load at depth 6.25
we will use the approximate method which is
[tex]V_{s} = \frac{qBL}{(B +Z)(L+Z)}[/tex] ------- (1)
q = 150 kN/m^2
B = 2.5 m
L = 5 m
Z = 6.25 m
substitute the given values into the equation (1) above
hence the Vs ( vertical stress ) = 19.0476 kN/m^2
1:
Determine the dynamic pressure of water received at the site described below.
Water Tower holds water at an elevation of 265 feet
Site is at an elevation of 145 feet
The water supply system uses cast iron pipes.
The water travels through 3.2 miles of pipes before reaching the site
The pipe has a diameter of 8 inches
The water travels through 9 90-degree bends, 4 Branch tees, and 1 Swing Check Valve
The water has a flow rate of 105 gpm
Round to the hundredths place (2 places after the decimal)
2:
What is the static head of a water supply system if the water tower holds water at and elevation of 462 feet and the site that uses the water is at an elevation of 294 feet?
Answer value
Answer:
20.87 Pa
Explanation:
The formula for dynamic pressure is given as;
q= 1/2*ρ*v²
where ;
q=dynamic pressure
ρ = density of fluid
v = velocity of fluid
First find v by applying the formula for flow rate as;
Q = v*A where ;
Q= fluid flow rate
v = flow velocity
A= cross-sectional area.
A= cross-sectional vector area of the pipe given by the formula;
A= πr² = 3.14 * 4² = 50.27 in² where r=radius of pipe obtained from the diameter given divided by 2.
Q = fluid flow rate = 105 gpm----change to m³/s as
1 gpm = 0.00006309
105 gpm = 105 * 0.00006309 = 0.006624 m³/s
A= cross-sectional vector area = 50.27 in² -------change to m² as:
1 in² = 0.0006452 m²
50.27 in² = 50.27 * 0.0006452 = 0.03243 m²
Now calculate flow velocity as;
Q =v * A
Q/A = v
0.006624 m³/s / 0.03243 m² =v
0.2043 m/s = v
Now find the dynamic pressure q given as;
q= 1/2 * ρ*v²
q= 1/2 * 1000 * 0.2043² = 20.87 Pa
A room is filled with saturated moist air at 25°C and a total pressure of 100 kPa. If the mass of dry air in the room is 100 kg, the mass of water vapor is:_______
a. 0.52 kg
b. 1.97 kg
c. 2.96 kg
d. 2.04 kg
e. 3.17 kg
Answer:the mass of water vapor is=d. 2.04 kg
Explanation:
The humidity ratio by mass is given as
x = mw / ma (1)
where
mw = mass of water vapor
ma = mass of dry air
And also humidity ratio by pressure by Ideal Gas Law is given as
x = 0.62198 pw / (pa - pw) (2)
where
pw = partial pressure of water vapor in moist air
pa = atmospheric pressure of moist air
Equating both equation we have that
Humidity ratio = 0.62198 pw / (pa - pw)= mw / ma (3)
From the from the water table at 25°C,
water vapor partial pressure = 23.8 torr
1 atm =760 torr.
1 atm = 101.325 kPa,
So, 760 torr =101.325 kPa,
Therefore 23.8 torr =3.173kPa
Humidity ratio = 0.62198 pw / (pa - pw)= mw / ma
0.62198 x 3.173 / (100-3.173)= mw / 100
1.9736 /96.827=mw/100
0.0204=mw/100
mw=2.04kg
A well is located in a 20.1-m thick confined aquifer with a conductivity of 14.9 m/day and a storativity of 0.0051. If the well is pumped at a constant rate of 500 gpm, what is the drawdown at a distance of 7.0 m from the well after 1 day of pumping?
Answer:
S = 5.7209 M
Explanation:
Given data:
B = 20.1 m
conductivity ( K ) = 14.9 m/day
Storativity ( s ) = 0.0051
1 gpm = 5.451 m^3/day
calculate the Transmissibility ( T ) = K * B
= 14.9 * 20.1 = 299.5 m^2/day
Note :
t = 1
U = ( r^2* S ) / (4*T* t )
= ( 7^2 * 0.0051 ) / ( 4 * 299.5 * 1 ) = 2.0859 * 10^-4
Applying the thesis method
W(u) = -0.5772 - In(U)
= 7.9
next we calculate the pumping rate from well ( Q ) in m^3/day
= 500 * 5.451 m^3 /day
= 2725.5 m^3 /day
Finally calculate the drawdown at a distance of 7.0 m form the well after 1 day of pumping
S = [tex]\frac{Q}{4\pi T} * W (u)[/tex]
where : Q = 2725.5
T = 299.5
W(u) = 7.9
substitute the given values into equation above
S = 5.7209 M
What are ethics in the engineering sector?
Answer:
Engineering ethics is the field of a system of moral principles that apply to the practice of engineering. The field examines and sets the obligations by engineers to society, to their clients, and to the profession.
Explanation:
1. Every employer shall keep the records of all accidents, dangerous occurrences, occupation
diseases and occupational poisoning at the workplace for
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Which option identifies the step skipped in the following scenario?
Eric is a newly hired engineer who has just ruined a prototype of a very expensive jet plane made from steel. He was short on time, so he rushed the molds of the body of the jet, causing them to crack. The cost incurred put the project far over budget.
He deviated from the design plans of the project.
He did not use the proper materials for the project.
He did not pay attention to the cost analysis of the project.
He did not allow the metal to cool properly when making molds.
Answer:
he didn't use the proper material
Answer:
A. He did not allow the metal to cool properly when making molds.
Explanation:
Propylene (C3H6) is burned with 50 percent excess air during a combustion process. Assuming complete combustion and a total pressure of 105 kPa. Determine:
a. the air-fuel ratio
b. the temperature at which the water vapor in the products will start condensing.
Answer:
44.59°c
Explanation:
Given data :
Total pressure = 105 kpa
complete combustion
A) Determine air-fuel ratio
A-F = [tex]\frac{N_{air} }{N_{fuel} } = \frac{(Nm)_{air} }{(Nm)_{c} (Nm)_{n} }[/tex]
N = number of mole
m = molar mass
A-F = [tex]\frac{(6.75*4.76)kmole * ( 29kg/mol)}{(3kmole)* 12kg/mol + (6kmol)*(1kg/mol)}[/tex] = 22.2 kg air/fuel
hence the ratio of Fuel-air = 1 : 22.2
B) Determine the temperature at which water vapor in the products start condensing
First we determine the partial pressure of water vapor before using the steam table to determine the corresponding saturation temp
partial pressure of water vapor
Pv = [tex]\frac{(N_{water vapor}) }{N_{pro} } * ( P_{ro} )[/tex]
N watervapor ( number of mole of water vapor ) = 3
N pro ( total number of mole of product = 3 + 3 + 2.25 + 25.28 = 33.53 kmol
Pro = 105
hence Pv = ( 3/33.53 ) * 105 = 9.39kPa
from the steam pressure table the corresponding saturation temperature to 9.39kPa = 44.59° c
Temperature at which condensing will start = 44.59°c
An equation showing the products of propylene with their mole numbers is attached below
When water levels on the exterior of a building exceed water levels on the interior, hydrostatic loads become:_______
Answer: more dense
Explanation:
What was a campaign belief in the 1980 presidential election? Carter called for a stronger national defense. Carter promised to appoint a woman to the Supreme Court. Reagan endorsed a conservative economic policy. Reagan supported the Equal Rights Amendment.
Answer:
C-Reagan endorsed a conservative economic policy.
Explanation:
edge21
Reagan endorsed a conservative economic policy.
What is Presidential election?In the US, presidential elections take place every four years. The next election for the nation's top position will be in 2024 because the last one occurred in 2020.
Federal elections must take place "the Tuesday next after the first Monday in November," according to U.S. law code.
Every even-numbered year has a presidential election and a congressional midterm election (e.g. 2016, 2018, 2020.)
Therefore, Reagan endorsed a conservative economic policy.
To learn more about economic policy, refer to the link:
https://brainly.com/question/22324594
#SPJ6
You have a 12 volt power source running through a circuit that has 3kΩ of resistance, how many amps (in mA) can flow through the circuit?
Answer:
4mA
Explanation:
For this problem, we will simply apply Ohm's law:
V = IR
V/R = I
I = V / R
I = 12 volt / 3kΩ
I = 4mA
Hence, the current in the circuit is 4mA.
Cheers.
Explain the major differences between designing buildings for earthquake resistance and for wind resistance.
Answer:
Earthquake's put vibration and seismic load on a building while wind puts a continuous force throughout the whole structure.
Explanation:
The most important difference between the design of a building that's resistent to earthquakes and resistant to high speed winds is that earthquake's put vibration and seismic load on a building while wind puts a continuous force throughout the whole structure.
Earthquake resistent building are equipped with a base that is isolated from the buildings with several layers of different material which absorb the vibration of the seismic waves and prevent them from reaching to the building.
Wind resistent buildings must have strong foundations and a sturdy structure/material that can withstand high pressure that the wind applies during events such as hurricanes.
I hope this answer helps.
What did the US and USSR agree on in the INF Treaty? They agreed to reduce nuclear weapons. They agreed that new European nations would be democratic. They agreed to tear down the Berlin Wall. They agreed that the USSR should break into several countries.
Answer:
they agreed to reduce nuclear weapons
Answer:
A
Explanation:
Edu 2023
3 mA are flowing through an 18 V circuit, how much resistance (in kΩ) is in that circuit?
Answer:
6kΩ
Explanation:
If we assume that the entire circuit's current is 3 mA, then we can compute the resistance within the circuit with the application of Ohm's law:
V = IR
V/I = R
R = V / I
R = 18V / 3 mA
R = 6kΩ
Hence, the resistance of the circuit is 6kΩ.
Cheers.
You have a 20 Volt power source attached to a light bulb that you've measured has a resistance of 8 Ohms, what is the power output of this light bulb (in Watts)?
Answer:
50 Watts
Explanation:
For this problem, we simply apply Ohm's law:
V = IR
V / R = I
P = IV
P = ( V / R ) V
P = ( V^2 / R )
P = (20 V)^2 / 8 Ω
P = 400 V^2 / 8 Ω
P = 50 Watts
Hence, the power consumed by the lightbulb is 50 Watts.
Cheers.
A 0.5 m rod of some material elongates 0.1 mm on heating from 20 to 112°C. Determine the value of the linear coefficient of thermal expansion [in (°C)-1] for this material.
Answer:linear coefficient of thermal expansion of the rod =2.17 x10^-6(°C)^-1
Explanation:
The Linear thermal expansion is calculated as
ΔL = αLΔT,
where ΔL = change in length L,
ΔT = the change in temperature,
α is the coefficient of linear expansion
Change in length ΔL= 0.1 mm =0.1/1000= 0.0001m
change in temperature,ΔT= Final - Initial temperature
= (112- 20)°C=92°C
Solving, we have that
ΔL = αLΔT
α=ΔL/LΔT
= 0.0001 / 0.5 x 92
=0.0001/46
=2.17 x10^-6 / °C
The linear coefficient of thermal expansion of the rod, α =2.17 x10^-6(°C)^-1
How does a project differ from an ongoing work effort?
Answer:
Projects have a fixed budget, while operations have to earn a profit to run the business. Projects are executed to start a new business objective and terminated when it is achieved, while operational work does not produce anything new and is ongoing.
Hope this helped!
If a person runs a distance of 0.7 km in 3 min, what is his average speed in kilometres/hour
Answer:
14 km/hour
Explanation:
A metal shear can be used to cut flat stock , round stock , channel iron and which of the following?
Answer:
Angle Iron
Explanation:
Mark brainliest please.
Tech a says you should push the wrench when braking a fastener loose. Tech b says that you should pull the wrench when braking a fastener loose. Who is correct?
Answer:
tech b because gut feeling
Explanation:
A pointer is spun on a fair wheel of chance having its periphery labeled Trom 0 to 100. (a) Whhat is the sample space for this experiment? (b)What is the probability that the pointer will stop between 20 and 35? (c) What is the probability that the wheel will stop on 58?
Answer:
A pointer is spun on a fair wheel of chance having its periphery labeled Trom 0 to 100. (a) Whhat is the sample space for this experiment? (b)What is the probability that the pointer will stop between 20 and 35? (c) What is the probability that the wheel will stop on 58?
Explanation:
thats all you said
Answer:
hii my name is RAGHAV what is your name
Explanation:
this question is which chapter
11. Technicians A and B are discussing
hybrid engines. Technician A says that idle
stop in HEVs and EREVs is a safety feature
for technicians. Technician B says that
high viscosity engine oil should be used
with most hybrid electric vehicles. Who is
correct?
O A. Technician A
B. Technician B
C. Neither Technician A nor B
D. Both Technicians A and B
Answer:
C. Neither Technician A nor B
Explanation:
Just took the test
You have a motor that runs at 1.5 amps from a 12 volt power source, how many watts of power is it using?
Answer:
18 Watts
Explanation:
For this problem, we simply need to understand the relationship of power to voltage and current. This relationship is derived from Ohm's law:
Power = Voltage * Current
Given this equation, we can say the following to find the power consumption of the motor:
Power = 12volts * 1.5amps
Power = 18 Watts
Hence, the motor is consuming 18 Watts of power.
Cheers.
Samantha is reviewing an engineer’s résumé for a design project involving equipment for an agricultural firm. What is it that she is looking for in his résumé?
The engineer must have humility.
The engineer must be a civil engineer.
The engineer must have the proper credentials.
The engineer must use materials from the US Green Building Council.
Answer:
i would say C
Explanation:
Answer:
c
Explanation:
ye
sup 100 point for you
Answer:
thanks! :D
Have a good day!
Answer:
Yay, :)
Thank you!!!
What prevented this weld from becoming ropey?
A lower ampera
A higher voltage
The position of the weld
The stepping motion of the weld
Answer:
If I am not mistaken I believe it is a higher voltage.
Explanation:
Hope this helps