Answer:
The total amount of heat generated;Q' = 2067 Btu/h
Explanation:
We are given;
Water entering temperature;T1 = 70°F
Water leaving temperature;T2 = 105°F
average velocity of water;V = 40 ft/min
Diameter of tube;D = 0.25 in = 0.25/12 ft = 0.02083 ft
Water density;ρ = 62.1 lbm/ft³
cp = 1.00 Btu/lbm·°F.
Now, the mass flow rate of the water is calculated from;
m' = ρAV
Where ρ is density, A is area and V is velocity
Area = πD²/4 = π*0.02083²/4 = 0.00034077555 ft²
m' = 62.1 * 0.00034077555 * 40
m' = 0.8465 lbm/min
Converting to lbm/hr = 0.8465 * 60 = 50.79 lbm/hr
From energy balance equation, we have;
E_in = E_out
So,
Q_in,w + m'h1 = m'h2
Q_in,w = m'h2 - m'h1
Q_in,w = m'(h2 - h1)
Now, m'(h2 - h1) can be written as;
m'cp(T2 - T1).
Thus ;
Q_in,w = m'cp(T2 - T1)
Plugging in the relevant values, we have;
Q_in,w = (50.79*1)(105 - 70)
Q_in,w = 1777.65 Btu/h
We are told that remaining 86 percent of heat generaged is removed by the cooling water. Thus;
The total amount of heat generated could be defined as;
Q' = Q_in,w/0.86
Q' = 1777.65/0.86
Q' = 2067 Btu/h
How does a car batteray NOT die?
Answer:
bye hooking plugs up to it to amp it up
Suppose you have a coworker who is a high Mach in your workplace. What could you do to counter the behavior of that individual? Put the high Mach individual in charge of a project by himself, and don’t let others work with him. Set up work projects for teams, rather than working one on one with the high Mach person. Work with the high Mach individual one on one, rather than in a team setting. Explain to the high Mach individual what is expected of him and ask him to agree to your terms.
Answer:
To counter the behavior of a high Mach individual in my workplace, I could put the individual in charge of a project by himself, and don't let others work with him.
Explanation:
A high Mach individual is one who exhibits a manipulative and self-centered behavior. The personality trait is characterized by the use of manipulation and persuasion to achieve power and results. But, such individuals are hard to be persuaded. They do not function well in team settings and asking them to agree to terms is very difficult. "The presence of Machiavellianism in an organisation has been positively correlated with counterproductive workplace behaviour and workplace deviance," according to wikipedia.com.
Mach is an abbreviation for Machiavellianism. Machiavellianism is referred to in psychology as a personality trait which sees a person so focused on their own interests that they will manipulate, deceive, and exploit others to achieve their selfish goals. It is one of the Dark Triad traits. The others are narcissism and psychopathy, which are very dangerous behaviors.
is sampled at a rate of to produce the sampled vector and then quantized. Assume, as usual, the minimum voltage of the dynamic range is represented by all zeros and the maximum value with all ones. The numbers should increase in binary order from bottom to top. Find the bit combination used to store each sample when rounded to the nearest integer between and (clipping may occur). Note: A partially-correct answer will not be recognized. You must answer all three correctly on the same
Answer:
d[0] = 11111111
d[1] = 11011101
d[2] = 1111011
Explanation:
Assume that the number of bits is 8. The voltage range input is -8 to 7 volts. The range is thus 15V, and the resolution is 15/2^8 = 0.0586 volts. We will first add +8 to the input to convert it to a 0-15v signal. Then find the equivalent bit representation. For 7.8 volts, the binary signal will be all 1's, since the max input voltage for the ADC is 7 volts. For 4.95, we have 4.95+8 = 12.95 volts. Thus, N = 12.95/0.0586 = 221. The binary representation is 11011101. For -0.8, we have -0.8 + 8 = 7.2. Thus, N = 7.2/0.0586 = 123. The binary representation is 1111011.
Thus,
d[0] = 11111111
d[1] = 11011101
d[2] = 1111011
The amusement park ride consists of a fixed support near O, the 6-m arm OA, which rotates about the pivot at O, and the compartment, which remains horizontal by means of a mechanism at A. At a certain instant, β=30ο, 2 0.75 rad/s, and 0.5 rad/s , all clockwise. Determine the horizontal and vertical forces (F and N) exerted by the bench on the 75-kg rider at P. Compare your results with the static values of these forces. (Use x-y coordinate system and vector equations
Answer:
Check the explanation
Explanation:
Kindly check the attached image below to see the step by step explanation to the question above.
The spherical pressure vessel has an inner diameter of 2 m and a thickness of 10 mm. A strain gauge having a length of 20 mm is attached to it, and it is observed to increase in length by 0.012 mm when the vessel is pressurized. Determine the pressure causing this deformation, and find the maximum in-plane shear stress, and the absolute maximum shear stress at a point on the outer surface of the vessel. The material is steel, for which Est
Question:
The spherical pressure vessel has an inner diameter of 2 m and a thickness of 10 mm. A strain gage having a length of 20 mm is attached to it, and it is observed to increase in length by 0.012 mm when the vessel is pressurized. Determine the pressure causing this deformation, and find the maximum in-plane shear stress, and the absolute maximum shear stress at a point on the outer surface of the vessel. The material is steel, for which Eₛₜ = 200 GPa and vₛₜ = 0.3.
Answer:
See explanation below
Explanation:
Given:
d = 2m = 2*10³ = 2000
thickness, t = 10 mm
Length of strain guage = 20 mm
i) Let's calculate d/t
[tex] \frac{d}{t} = \frac{2000}{10} = 200 [/tex]
Since [tex] \frac{d}{t}[/tex] is greater than length of strain guage, the pressure vessel is thin.
For the minimum normal stress, we have:
[tex] \sigma max= \frac{pd}{4t} [/tex]
[tex] \sigma max= \frac{2000p}{4 * 20} [/tex]
= 50p
For the minimum normal strain due to pressure, we have:
[tex] E_max= \frac{change in L}{L_g} [/tex]
[tex] = \frac{0.012}{20} = 0.60*10^-^3[/tex]
The minimum normal stress for a thin pressure vessel is 0.
[tex] \sigma _min = 0 [/tex]
i) Let's use Hookes law to calculate the pressure causing this deformation.
[tex] E_max = \frac{1}{E} [\sigma _max - V(\sigma _initial + \sigma _min)] [/tex]
Substituting figures, we have:
[tex] 0.60*10^-^3 = \frac{1}{200*10^9} [50p - 0.3 (50p + 0)] [/tex]
[tex] 120 * 10^6 = 35p [/tex]
[tex] p = \frac{120*10^6}{35}[/tex]
[tex] p = 3.429 * 10^6 [/tex]
p = 3.4 MPa
ii) Calculating the maximum in-plane shear stress, we have:
[tex] \frac{\sigma _max - \sigma _int}{2}[/tex]
[tex] = \frac{50p - 50p}{2} = 0 [/tex]
Max in plane shear stress = 0
iii) To find the absolute maximum shear stress at a point on the outer surface of the vessel, we have:
[tex] \frac{\sigma _max - \sigma _min}{2}[/tex]
[tex] = \frac{50p - 0}{2} = 25p [/tex]
since p = 3.429 MPa
25p = 25 * 3.4 MPa
= 85.71 ≈ 85.7 MPa
The absolute maximum shear stress at a point on the outer surface of the vessel is 85.7 MPa
A heat recovery device involves transferring energy from the hot flue gases passing through an annular region to pressurized water flowing through the inner tube of the annulus. The inner tube has inner and outer diameters of 24 and 30 mm and is connected by eight struts to an insulated outer tube of 60-mm diameter. Each strut is 3 mm thick and is integrally fabricated with the inner tube from carbon steel (k 50 W/m K). Consider conditions for which water at 300 K flows through the inner tube at 0.161 kg/s while flue gases at 800 K flow through the annulus, maintaining a convection coefficient of 100 W/m2 K on both the struts and the outer surface of the inner tube. What is the rate of heat transfer per unit length of tube from gas to the water?
Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem.
Explain why failure of this garden hose occurred near its end and why the tear occurred along its length. Use numerical values to explain your result. Assume the water pressure is 30 psistr
Answer:
hoop stresslongitudinal stressmaterial usedall this could led to the failure of the garden hose and the tear along the length
Explanation:
For the flow of water to occur in any equipment, water has to flow from a high pressure to a low pressure. considering the pipe, water is flowing at a constant pressure of 30 psi inside the pipe which is assumed to be higher than the allowable operating pressure of the pipe. but the greatest change in pressure will occur at the end of the hose because at that point the water is trying to leave the hose into the atmosphere, therefore the great change in pressure along the length of the hose closest to the end of the hose will cause a tear there. also the other factors that might lead to the failure of the garden hose includes :
hoop stress ( which acts along the circumference of the pipe):
αh = [tex]\frac{PD}{2T}[/tex] EQUATION 1
and Longitudinal stress ( acting along the length of the pipe )
αl = [tex]\frac{PD}{4T}[/tex] EQUATION 2
where p = water pressure inside the hose
d = diameter of hose, T = thickness of hose
we can as well attribute the failure of the hose to the material used in making the hose .
assume for a thin cylindrical pipe material used to be
[tex]\frac{D}{T}[/tex] ≥ 20
insert this value into equation 1
αh = [tex]\frac{20 *30}{2}[/tex] = 60/2 = 30 psi
the allowable hoop stress was developed by the material which could have also led to the failure of the garden hose
Determine the drag on a small circular disk of 0.02-ft diameter moving 0.01 ft/s through oil with a specific gravity of 0.89 and a viscosity 10000 times that of water. The disk is oriented normal to the upstream velocity. By what percent is the drag reduced if the disk is oriented parallel to the flow?
Answer:
33.3%
Explanation:
Given that:
specific gravity (SG) = 0.89
Diameter (D) = 0.01 ft/s
Density of oil [tex]\rho= SG\rho _{h20} = 0.89 * 1.94=1.7266\frac{sl}{ft^3}[/tex]
Since the viscosity 10000 times that of water, The reynold number [tex]R_E=\frac{\rho VD}{\mu} =\frac{1.7266*0.01*0.01}{0.234}=7.38*10^{-4}[/tex]
Since RE < 1, the drag coefficient for normal flow is given as: [tex]C_{D1}=\frac{24.4}{R_E}= \frac{20.4}{7.38*10^{-4}}=2.76*10^4[/tex]
the drag coefficient for parallel flow is given as: [tex]C_{D2}=\frac{13.6}{R_E}= \frac{13.6}{7.38*10^{-4}}=1.84*10^4[/tex]
Percent reduced = [tex]\frac{D_1-D_2}{D_2} *100=\frac{2.76-1.84}{3.3}=33.3[/tex] = 33.3%
Tech A says that when checking tire pressure, the tire should be " cold." Tech B says that the tires should be driven more than 3 miles before checking tire presure. Who is correct?
Answer: Technician A is correct.
Explanation:
Technician A is correct because temperature of a tire will affect its pressure reading.
Tires attract heat because of their dark colour and then motion on the road generates heat. A car owner or technician should know that tire pressure is most accurate when the tire is cold (especially when atmospheric temperature is cool too).
If the tires are driven three miles first, their temperature will be high (due to the rubbing of the tires on the surface of the road). This higher temperature will result in higher per square inch (psi) readings.
Temperature has a great influence on the tire pressure.
Even if the tire is driven up to or more than 3 miles, it should still be left to cool, before tire pressure is checked.
The tire manufacturer's rating should be the maximum possible tire pressure. If an abnormal reading is gotten, the gauge should be properly checked.
For what type of metal is high speed steel drill best suited?
Answer:
high speed steel I believe
For an Ac signal with peak voltage Vp equal to 60V, the same power would be delivered to a load with a dc voltage of
Answer:
30√2 ≈ 42.426 volts
Explanation:
The RMS value of the signal is the DC equivalent. For a sine wave, the mean of the square is half the square of the peak value. Then the Root-Mean-Square is ...
RMS = √((Vp)^2/2) = Vp/√2
For Vp = 60 volts, the equivalent DC voltage is ...
V = (60 volts)/√2 = 30√2 volts ≈ 42.426 volts
(a) Show how two 2-to-1 multiplexers (with no added gates) could be connected to form a 3-to-1 MUX. Input selection should be as follows: If AB = 00, select I0 If AB = 01, select I1 If AB = 1− (B is a don’t-care), select I2 (b) Show how two 4-to-1 and one 2-to-1 multiplexers could be connected to form an 8-to-1 MUX with three control inputs. (c) Show how four 2-to-1 and one 4-to-1 multiplexers could be connected to form an 8-to-1 MUX with three control inputs
Answer:
Explanation:
a) Show how two 2-to-1 multiplexers (with no added gates) could be connected to form a 3-to-1 MUX. Input selection should be as follows: If AB = 00, select I0 If AB = 01, select I1 If AB = 1− (B is a don’t-care), select I2
We are to show how Two-2-to -1 multiplexers could be connected to form 3-to-1 MUX
If AB = 00 select [tex]I_o[/tex]
If AB = 01 select [tex]I_1[/tex]
If AB = 1_(B is don't care), select [tex]I_2[/tex]
However, the truth table is attached and shown in the first file below.
Also, the free- body diagram for 2- to - 1 MUX is shown in the second diagram attached below.
b) We are show how two 4-to-1 and one 2-to-1 multiplexers could be connected to form an 8-to-1 MUX with three control inputs.
The perfect illustration showing how they are connected in displayed in the third free-body diagram attached below.
Where ; [tex]I_o , I_1, I_2, I_3, I_4, I_5, I_6, I_7[/tex] are the inputs of the multiplexer and Z is the output.
c) Show how four 2-to-1 and one 4-to-1 multiplexers could be connected to form an 8-to-1 MUX with three control inputs.
For four 2-to-1 and one 4-to-1 multiplexers could be connected to form an 8-to-1 MUX with three control inputs, we have a perfect illustration of the diagram in the last( which is the fourth) diagram attached below.
Where ; [tex]I_o , I_1, I_2, I_3, I_4, I_5, I_6, I_7[/tex] are the inputs of the multiplexer and Z is the output
This question is a multiplexer which is a topic in digital circuit.
Multiplexer is a type of combination circuit that consist of a maximum of [tex]2^n[/tex] data inputs 'n' selection lines and single output line. One of these data inputs will be connected to the output based on the values of selection lines. Another name for multiplexers is MUX.
If we have 'n' selection lines, we will get [tex]2^n[/tex] possible combinations zero and ones. Each combination will select a maximum of only one data input.
a)
Two 2-to-1 multiplexers to form a 3-to-1 MUX.
If AB = 00, select [tex]I_o[/tex]
If AB = 01, select [tex]I_1[/tex]
If AB = 1- (B is don't care) select I
The truth table for the above scenario is in the attached document below.
Figure 1 and 2 represents the solution to this question.
b).
Two 4-to-1 multiplexers and one 2-to-1 multiplexers and one 2-to-1 multiplexers are used to form an 8-to-1 MUX.
In the attached diagram, figure 3 shows a comprehensive detail of how it is structured.
Where [tex]I_o[/tex] to [tex]I_7[/tex] are the inputs of the multiplexer and Z is the output.
c) Four 2-to-1 multiplexers and one 4-to -1 multiplexer are used to form 8-to-1 MUX.
In the attached diagram, figure 4 shows how it is structured.
We would see that [tex]I_o[/tex] to [tex]I_7[/tex] are the inputs of the multiplexer and Z is the output in the system.
Learn more about multiplexers here;
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g In the above water treatment facility, chemical concentration (mg/gal) within the tank can be considered uniform. The initial chemical concentration inside the tank was 0 mg/gal, the concentration of effluent coming in is 10 mg/gal. The volume of the tank is 10,000 gallons. The fluid coming in rate is equal to fluid going out is equal to 50 gal/min. Establish a dynamic model of how the concentration of the chemical inside the tank increases over time.
Answer:
0.05 mg / gallon
Explanation:
mass of chemecila coming in per minute = 50*10 = 500 mg/min
at a time t min , M = mass of chemical = 500*t mg
conecntartion of chemecal = 500t/10000 = 0.05 mg / gallon
A thin‐walled tube with a diameter of 12 mm and length of 25 m is used to carry exhaust gas from a smoke stack to the laboratory in a nearby building for analysis. The gas enters the tube at 200°C and with a mass flow rate of 0.006 kg/s. Autumn winds at a temperature of 15°C blow directly across the tube at a velocity of 2.5 m/s. Assume the thermophysical properties of the exhaust gas are those of air
Estimate the average heat transfer coefficient for the exhaust gas flowing inside the tube.
Answer:
The average heat transfer coefficient for the exhaust gas flowing inside the tube, h = 204.41 W/m^2 - K
Explanation:
The detailed solution is attached as files below.
However, the steps followed are highlighted:
1) The average temperature was calculated as 380.5 K
2) The properties of air at 380.5 K was highlighted
3) The Prandti number was calculated. Pr = 0.693
4) The Reynold number was calculated, Re = 28716.77
5) The Nusselt umber was calculated, Nu = 75.94
6) From Nu = (hD)/k , the average heat transfer coefficient, h, was calculated and a value of 204.41 W/m^2 - K was gotten.
Have you ever had an ice cream headache that’s when a painful sensation resonates in your head after eating something cold usually ice cream on a hot day this pain is produced by the dilation of a nerve center in the roof of your mouth the nerve center is overreacting to the cold by trying to hit your brain ice cream headaches have turned many smiles to frowns identify the structure
Answer:
Cause and effect
Explanation:
pls mark brainliest
The structure that makes or turned many smiles to frowns can be regarded as compare/contrast.
What is compare contrast?The term compare/contrast is a common terms. The act of comparing is known to be depicting the similarities, and contrasting is said to be showing differences that exist between two things.
Conclusively, from the above, we can see that it is a compare/contrast scenario as it talks about the effects of taking ice cream. It went from smiles to frowns.
See option below
cause/effect
descriptive
compare/contrast
sequence/process
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Find a negative feedback controller with at least two tunable gains that (1) results in zero steady state error when the input is a unit step (1/s). (and show why it works); (2) Gives a settling time of 4 seconds; (3) has 10% overshoot. Use the standard 2nd order approximation. Plot the step response of the system and compare the standard approximation with the plot.
Answer:
Gc(s) = [tex]\frac{0.1s + 0.28727}{s}[/tex]
Explanation:
comparing the standard approximation with the plot attached we can tune the PI gains so that the desired response is obtained. this is because the time requirement of the setting is met while the %OS requirement is not achieved instead a 12% OS is seen from the plot.
attached is the detailed solution and the plot in Matlab
The supplement file* that enclosed to this homework consists Time Versus Force data. The first column in the file stands for time (second) and the 2nd stands for force (Volt), respectively. This data were retrieved during an impact event. In this test, an impactor strikes to a sample. A force-ring sensor that attached to the impactor generates voltage during collision. A data acquisition card gathers the generated signals.
• Take the mass of the impactor as 30 kg and strike velocity as 2.0 m/s.
• Pick the best numerical technique, justify your choice.
• All results must be in SI units.
a) Determine a factor that will be used in the conversion from V to N. The calibration data that supplied by manufacturer as below:
• Take the mass of the impactor as 30 kg and strike velocity as 2.0 m/s.
• Pick the best numerical technique, justify your choice.
• All results must be in SI units.
a) Determine a factor that will be used in the conversion from V to N. The calibration data that supplied by manufacturer as below:• Take the mass of the impactor as 30 kg and strike velocity as 2.0 m/s.
• Pick the best numerical technique, justify your choice.
• All results must be in SI units.
a) Determine a factor that will be used in the conversion from V to N. The calibration data that supplied by manufacturer as below:
b) Compute the impulse of this event.
c) Obtain acceleration, velocity and displacement histories by using Newton’s second law of motion.
d) Compute the absorbed energy during collision.
Answer:
A.) 1mv = 2000N
B.) Impulse = 60Ns
C.) Acceleration = 66.67 m/s^2
Velocity = 4 m/s
Displacement = 0.075 metre
Absorbed energy = 60 J
Explanation:
A.) Using a mathematical linear equation,
Y = MX + C
Where M = (2000 - 0)/( 898 - 0 )
M = 2000/898
M = 2.23
Let Y = 2000 and X = 898
2000 = 2.23(898) + C
2000 = 2000 + C
C = 0
We can therefore conclude that
1 mV = 2000N
B.) Impulse is the product of force and time.
Also, impulse = momentum
Given that
Mass M = 30kg
Velocity V = 2 m/s
Impulse = M × V = momentum
Impulse = 30 × 2 = 60 Ns
C.) Force = mass × acceleration
F = ma
Substitute force and mass into the formula
2000 = 30a
Make a the subject of formula
a = 2000/30
acceleration a = 66.67 m/s^2
Since impulse = 60 Ns
From Newton 2nd law,
Force = rate of change in momentum
Where
change in momentum = -MV - (- MU)
Impulse = -MV + MU
Where U = initial velocity
60 = -60 + MU
30U = 120
U = 120/30
U = 4 m/s
Force = 2000N
Impulse = Ft
Substitute force and impulse to get time
60 = 2000t
t = 60/2000
t = 0.03 second
Using third equation of motion
V^2 = U^2 + 2as
Where S = displacement
4^2 = 2^2 + 2 × 66.67S
16 = 4 + 133.4S
133.4S = 10
S = 10/133.4
S = 0.075 metre
D.) Energy = 1/2 mV^2
Energy = 0.5 × 30 × 2^2
Energy = 15 × 4 = 60J
What is Postflow used to protect?
Answer:
The idea is to protect the puddle while it cools
Explanation:
The asymmetric roof truss is of the type used when a near normal angle of incidence of sunlight onto the south-facing surface ABC is desirable for solar energy purposes. The five vertical loads represent the effect of the weights of the truss and supported roofing materials. The 390-N load represents the effect of wind pressure. Determine the equivalent force-couple system at A. The couple is positive if counterclockwise, negative if clockwise. Also, compute the x-intercept of the line of action of the system resultant treated as a single force R.
Answer:
[tex]R= 337.75\ \bar i - 2275 \ \bar j \ \ N[/tex]
[tex]\sum M_A = -13650 \ N.m[/tex]
x = 6 m
Explanation:
From the diagram attached below :
Equivalent force:
[tex]R= -260 \bar j + 390 \ cos 30 \bar{ i} - 390 \ sin 30 \bar j - 520 \ \bar j- 520 \ \bar j- 520 \ \bar j- 260 \ \bar j[/tex]
[tex]R= 337.75\ \bar i - 2275 \ \bar j \ \ N[/tex]
The equivalent couple at point A is as follows:
[tex]\sum M_A = -390(3)-520(\frac{6}{2})- 520({6})- 520(6+\frac{6}{2}) -260(12)[/tex]
[tex]\sum M_A = -13650 \ N.m[/tex]
By applying the principles of momentum :
[tex]\sum M_A = Ry(x)[/tex]
[tex]- 13650 = - 2275 \ x[/tex]
x = [tex]\frac{13650}{2275}[/tex]
x = 6 m
An insulated, vertical piston–cylinder device initially contains 10 kg of water, 6 kg of which is in the vapor phase. The mass of the piston is such that it maintains a constant pressure of 200 kPa inside the cylinder. Now steam at 0.5 MPa and 350°C is allowed to enter the cylinder from a supply line until all the liquid in the cylinder has vaporized. Determine (a) the final temperature in the cylinder and (b) the mass of the steam that has entered.
Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem.
A refrigerator uses refrigerant-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. The refrigerant enters the evaporator at 120 kPa with a quality of 34 percent and leaves the compressor at 70°C. If the compressor consumes 450 W of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the COP of the refrigerator
Answer:
(a) 0.0064 kg/s
(b) 800 KPa
(c) 2.03
Explanation:
The ideal vapor compression cycle consists of following processes:
Process 1-2 Isentropic compression in a compressor
Process 2-3 Constant-pressure heat rejection in a condenser
Process 3-4 Throttling in an expansion device
Process 4-1 Constant-pressure heat absorption in an evaporator
For state 4 (while entering compressor):
x₄ = 34% = 0.34
P₄ = 120 KPa
from saturated table:
h₄ = hf + x hfg = 22.4 KJ/kg + (0.34)(214.52 KJ/kg)
h₄ = 95.34 KJ/kg
For State 1 (Entering Compressor):
h₁ = hg at 120 KPa
h₁ = 236.99 KJ/kg
s₁ = sg at 120 KPa = 0.94789 KJ/kg.k
For State 3 (Entering Expansion Valve)
Since 3 - 4 is an isenthalpic process.
Therefore,
h₃ = h₄ = 95.34 KJ/kg
Since this state lies at liquid side of saturation line, therefore, h₃ must be hf. Hence from saturation table we find the pressure by interpolation.
P₃ = 800 KPa
For State 2 (Leaving Compressor)
Since, process 2-3 is at constant pressure. Therefore,
P₂ = P₃ = 800 KPa
T₂ = 70°C (given)
Saturation temperature at 800 KPa is 31.31°C, which is less than T₂. Thus, this is super heated state. From super heated property table:
h₂ = 306.9 KJ/kg
(a)
Compressor Power = m(h₂ - h₁)
where,
m = mass flow rate of refrigerant.
m = Compressor Power/(h₂ - h₁)
m = (0.450 KJ/s)/(306.9 KJ/kg - 236.99 KJ/kg)
m = 0.0064 kg/s
(b)
Condenser Pressure = P₂ = P₃ = 800 KPa
(c)
The COP of ideal vapor compression cycle is given as:
COP = (h₁ - h₄)/(h₂ - h₁)
COP = (236.99 - 95.34)/(306.9 - 236.99)
COP = 2.03
The Ph diagram is attached
A sheet of steel 4.4 mm thick has nitrogen atmospheres on both sides at 1200°C and is permitted to achieve a steady-state diffusion condition. The diffusion coefficient for nitrogen in steel at this temperature is 5.9 × 10^(-11) m^2/s, and the diffusion flux is found to be 4.7 × 10^(-7) kg/m^2.s. Also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4.5 kg/m^3.
How far into the sheet from this high-pressure side will the concentration be 2.7 kg/m^3? Assume a linear concentration profile.
Answer:
0.544×10–³
Explanation:
Please see the attached file for the solution
Air at 100°F, 1 atm, and 10% relative humidity enters an evaporative cooler operating at steady state. The volumetric flow rate of the incoming air is 1765 ft3/min. Liquid water at 68°F enters the cooler and fully evaporates. Moist air exits the cooler at 70°F, 1 atm. There is no significant heat transfer between the device and its surroundings and kinetic and potential energy effects can be neglected. Determine the mass flow rate at which liquid enters, in lb(water)/min.
Answer:
Check the explanation
Explanation:
Kindly check the attached image below to see the step by step explanation to the question above.
(USCS units) A deep drawing operation is performed on a sheet-metal blank that is 1/8 in thick. The height of the cup = 3.8 in and its diameter = 5.0 in (both inside dimensions).
(a) Assuming the punch radius = 0, compute the starting diameter of the blank to complete the operation with no material left in the flange.
(b) Is the operation feasible (ignoring the fact that the punch radius is too small)?
Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem
a) The current that goes through a 100 mH inductor is given as
i(t) = 6 - 2e^-2t A t >= 0
Find the voltage v(t) across the inductor.
b) The voltage v(t) = 5sin(5t) V is applied across the terminals of a 200 mH inductor. The initial current through the inductor is i(0) = -10 A. Find the current i(t) through the inductor for t > 0.
Answer:
A) V(t) = 0.4e^-2t
B) i(t) = (25tsin5t+10) A for t>0
Explanation:
Formula for calculating voltage across an inductor is expressed as:
V = Ldi/dt
Given L = 100mH = 100×10^-3
If i(t) = 6 - 2e^-2t A t >= 0
di/dt = (-2)(-2)e^-2t
di/dt = 4e^-2t
If t ≥ 0
V(t) = 100×10^-3 × (4e^-2t)
V(t) = 0.1×4e^-2t
V(t) = 0.4e^-2t for t≥0
B) Applying the same formula as above
V = Ldi/dt
Vdt = Ldi
V/L dt = di
On integration
Vt/L = i + C
When t = 0, i = -10A
Substituting the values into the formula
V(0)/L = -10 + C
0 = -10+C
C = 10
To get the current i(t) through the inductor for t>0,
Since Vt/L = i + C
Given V(t) = 5sin5t Volts
L = 200mH = 200×10^-3H
C = 10
On substituting
(5sin5t)t/0.2 = i + 10
25tsin5t = i + 10
i(t) = (25tsin5t-10) A for t>0
Two Electric field vectors E1 and E2 are perpendicular to each other; obtain its base
vectors.
Answer:
<E1, E2>.
Explanation:
So, in the question above we are given that the Two Electric field vectors E1 and E2 are perpendicular to each other. Thus, we are going to have the i and the j components for the two Electric Field that is E1 and E2 respectively. That is to say the addition we give us a resultant E which is an arbitrary vector;
E = |E| cos θi + |E| sin θj. -------------------(1).
Therefore, if we make use of the components division rule we will have something like what we have below;
x = |E2|/ |E| cos θ and y = |E1|/|E| sin θ
Therefore, we will now have;
E = x |E2| i + y |E1| j.
The base vectors is then Given as <E1, E2>.
A steady green traffic light means
Answer:
Its C. you may proceed, but only if the path is clear
Explanation:
I just gave Quiz and its correct
An air conditioning unit is used to provide cooling during summer for a house. If the air conditioner provides 450 kW cooling by using 150 kW electrical power, determine the coefficient of performance (COP) of the air conditioner. The outside temperature and inside temperature are 40 and 20°C, respectively. Using the inequality of Clausius determine if the cycle is possible. Determine the COP of an air conditioner working based on the Carnot cycle between the same temperature difference. Compare the COPs of the Carnot and actual air conditioners and comment on them based on your answer for the previous part (the inequality of
Answer:
See explaination
Explanation:
Please kindly check attachment for the step by step solution of the given problem.
Discuss the ethics of the circumstances that resulted in the Columbia shuttle disaster. Considering the predictions that were made years before the disaster, as well as the reliability of the Binomial distribution and its implications, what could or should the engineers associated with the program have done differently
Explanation:
This is not so much a mathematical issue as a case study, because the response will inevitably require us to test the special Columbic shuttle disaster scenario. I would suggest that you read this in detail and present the points accordingly. Here I give as many points as I think are relevant.
The failure of a space program is definitely a complex situation, more than a simple binomial distribution. It's definitely not as simple as repeating the flip of a coin. There are several coherent factors and situations that govern the overall coordination and execution of such an event. The problem is, those who are running a project like this are still making a trade off,It is never the case that they sealed the lid on any chance of failure between multiple parameters. You try to do something, but often, as is the case above, the potentially dangerous situation is impossible or uncontrollable. Since the root cause of failure, which is dried out tiles that can not withstand heat and water, it appears that owing to the constant use of the shuttle the head architects have not foreseen this.
Consider a Carnot heat pump cycle executed in a steady-flow system in the saturated mixture region using R-134a flowing at a rate of 0.264 kg/s. The maximum absolute temperature in the cycle is 1.15 times the minimum absolute temperature, and the net power input to the cycle is 5 kW. If the refrigerant changes from saturated vapor to saturated liquid during the heat rejection process, determine the ratio of the maximum to minimum pressures in the cycle.
Answer:
7.15
Explanation:
Firstly, the COP of such heat pump must be measured that is,
[tex]COP_{HP}=\frac{T_H}{T_H-T_L}[/tex]
Therefore, the temperature relationship, [tex]T_H=1.15\;T_L[/tex]
Then, we should apply the values in the COP.
[tex]=\frac{1.15\;T_L}{1.15-1}[/tex]
[tex]=7.67[/tex]
The number of heat rejected by the heat pump must then be calculated.
[tex]Q_H=COP_{HP}\times W_{nst}[/tex]
[tex]=7.67\times5=38.35[/tex]
We must then calculate the refrigerant mass flow rate.
[tex]m=0.264\;kg/s[/tex]
[tex]q_H=\frac{Q_H}{m}[/tex]
[tex]=\frac{38.35}{0.264}=145.27[/tex]
The [tex]h_g[/tex] value is 145.27 and therefore the hot reservoir temperature is 64° C.
The pressure at 64 ° C is thus 1849.36 kPa by interpolation.
And, the lowest reservoir temperature must be calculated.
[tex]T_L=\frac{T_H}{1.15}[/tex]
[tex]=\frac{64+273}{1.15}=293.04[/tex]
[tex]=19.89\°C[/tex]
the lowest reservoir temperature = 258.703 kpa
So, the pressure ratio should be = 7.15
