Answer:
T2 ( final temperature ) = 576.9 K
a) 853.4 kJ/kg
b) 1422.3 kJ / kg
Explanation:
given data :
pressure ( P1 ) = 90 kPa
Temperature ( T1 ) = 30°c + 273 = 303 k
P2 = 450 kPa
Determine final temperature for an Isentropic process
[tex]T2 = T1 (\frac{p2}{p1} )^{(k-1)/k}[/tex] ----------- ( 1 )
T2 = 303 [tex]( \frac{450}{90})^{(1.667- 1)/1.667}[/tex] = 576.9K
Work done in a piston-cylinder device can be calculated using this formula
[tex]w_{in} = c_{v} ( T2 - T1 )[/tex] ------- ( 2 )
where : cv = 3.1156 kJ/kg.k for helium gas
T2 = 576.9K , T1 = 303 K
substitute given values Back to equation 2
[tex]w_{in}[/tex] = 853.4 kJ/kg
work done in a steady flow compressor can be calculated using this
[tex]w_{in} = c_{p} ( T2 - T1 )[/tex]
where : cp ( constant pressure of helium gas ) = 5.1926 kJ/kg.K
T2 = 576.9 k , T1 = 303 K
substitute values back to equation 3
[tex]w_{in}[/tex] = 1422.3 kJ / kg
1. The final temperature for this reversible, adiabatic process is 576.82 Kelvin.
2a. Assuming the process took place in a piston-cylinder device, the work done is equal to 853.11 kJ/kg.
2b. Assuming the process took place in a steady-flow compressor, the work done is equal to 1422.82 kJ/kg.
Given the following data:
Initial pressure = 90 kPaFinal pressure = 450 kPaInitial temperature = 30°C to K = [tex]273 + 30 = 303 \;Kelvin[/tex]Constant, k = 1.667
Constant pressure for helium gas, [tex]C_p[/tex] = 5.1926 kJ/kg.K
Constant volume for helium gas, [tex]C_v[/tex] = 3.1156 kJ/kg.k
First of all, we would determine the final temperature for this isentropic process.
For an isentropic process, the final temperature is given by the formula:
[tex]T_2 = T_1 (\frac{P_2}{P_1})^{\frac{k-1}{k}}\\\\T_2 = 303 \times (\frac{450}{90})^{\frac{1.667-1}{1.667}}\\\\T_2 = 303 \times (5)^{\frac{0.667}{1.667}}\\\\T_2 = 303 \times 5^{0.40}\\\\T_2 = 303 \times 1.9037\\\\T_2 = 576.82 \;K[/tex]
a. In a piston-cylinder device, work done is given by the formula:
[tex]W = C_v(T_2 -T_1)\\\\W = 3.1156(576.82 -303)\\\\W = 3.1156 \times 273.82\\\\W = 853.11[/tex]
Work done, W = 853.11 kJ/kg
b. In a steady-flow compressor, work done is given by the formula:
[tex]W = C_p(T_2 -T_1)\\\\W = 5.1926(576.82 -303)\\\\W = 5.1926 \times 273.82\\\\W = 1422.82[/tex]
Work done, W = 1422.82 kJ/kg
Read more: https://brainly.com/question/22599382
How do statics, Dynamics and Mechanics of materials differ from each other? *
Answer:
Statics means study of all the forces couples moments etc. for a stationary object which is in the state of rest. Whereas Dynamics deals with study of all the forces when object is in motion . In mechanics static is referred to motion(velocity) which is either zero or constant.
Which of the following connects the middle ear to the back of the nose and helps keep the
pressure equal?
A: Eustachian tubes
B: Semicircular canals
C Eardrums
D: Ossicles
Which actions would the maintenance and operations crews carry out as a building is completed and preparing to open to the public? Select all that apply.
make any last minute repairs
install new equipment and furnishings
troubleshoot solutions to any lingering problems or malfunctions
determine which new residents or company employees will occupy which offices or residences
Answer:
1. make any last minute repairs
2. install new equipment and furnishings
3. troubleshoot solutions to any lingering problems or malfunctions
Explanation:
Given that the role or functions of maintenance and operations crews in building construction are to ensure that the building is maintained to the required standard of use.
This involves making sure that all repairs in a building are done. The equipment is properly installed and solved any form of equipment that malfunctions.
Hence, in this case, the correct answer is:
1. make any last-minute repairs
2. install new equipment and furnishings
3. troubleshoot solutions to any lingering problems or malfunctions
Answer:
1. make any last minute repairs
2. install new equipment and furnishings
3. troubleshoot solutions to any lingering problems or malfunctions
Explanation:
Which of the following can not be used to store an electrical charge?
The wood beam described below applies to Questions 15 through 17. A 2x10 wood beam is to support a service dead load (including beam self-weight) of 50 lbs/ft and a service live load of 60 lbs/ft (note that the loads given are per foot and not per square ft). The beam is part of a series of adjacent parallel beams spaced 16 inches apart. Span length is 15 ft. Assume that lateral buckling is prevented. Wood species/grade is "Red Maple", No. 1. Moisture content is less than 19% (dry). This member's service temperature is not elevated. What is the design moment strength (M'.) in kip-in? do not check bearing stresses and do not check deflection Shear strength is covered under the next question.
Question 16 For the wood beam described in Question 15, what is the design shear strength of the beam (V.) in kips? Pay attention to the requested unit!
Question 17 For the wood beam described in Questions 15 and 16, is the beam structurally adequate?
No
Yes
Not known with the information given
Answer:
1. Design moment = 30.83kip
2. Shear strength = 2.8kip
3. Yes beam is adequate.
Explanation:
Length = 15ft = 180 inches
Dead load = 50
Live load = 60
1.2x50+1.6x60
= 60+96
= 156
= 13 lbs/inch
Area = 2x10
= 20in²
Modulus Zx = bd²/6
= 2x10²/6
= 33.33in³
Bending strength = 925
Shear strength = 210
1. Design moment = 33.33x925
= 30830.25
= 30.83kip
Shear strength = 2/3*20*210
= 2800
= 2.8kip
3. Yes beam is adequate
Maximum bending moment = 2/8*13*180 = 52.65
52.65>30.83
Maximum shear
13x180/2<2.83
1.17kip<2.83kip
AC motor characteristics require the applied voltage to be proportionally adjusted by an AC drive whenever the frequency is changed. True or false?
Please help
What are saving bonds?
Briefly discuss the principle forms of communication that might be utilized in the construction industry?
Answer:
xcvjchjcnjkkhjmklk heyyyy biiiiiiiittcccchhh
The utility companies often sell electric power at night at much lower prices since the demand for electric power is usually much higher during the day. The owner of a four-story Hotel would like to take advantage of this opportunity. The owner decides to design a pump piping system that delivers water from the lake to the large pool (or reservoir) located on the roof of the Hotel. The owner wants to fill the pool from sea water during the night when the electric power is cheap and to use the water during the day.
Therefore, the owner decides to hire a mechanical engineer to design this piping pump system to deliver the water from the close lake to the reservoir on the roof of the building. As a hired mechanical engineer, you are supposed to design this piping pump system by selecting the desired pipe size, flow rate and all necessary fittings, and determine the horsepower of the pump required for such a delivery.
Answer:
the electric is cheaper
Explanation:
Seperate real and imaginary parts tan(2x+i3y)
Answer:
First you have to separate real and imaginary parts of Tan(x+iy)=Tan(z)=sin(z)/cos(z)
sinz=sin(x+iy)=sinxcos(iy)+cosxsin(iy)=sinxcoshy-icosx sinhy
cosz=cos(x+iy)=cosxcos(iy)-sinxsin(iy)=cosxcoshy−isinxsinhy
Now if you plug in Tan(z) and simplify (it is easy!) you get
Tan(z)=(sin(2x)+isinh(2y))/(cos(2x)+cosh(2y))= A+iB.
This means that
A=sin(2x)/(cos(2x)+cosh(2y)) and B= sinh(2y)/(cos(2x)+cosh(2y))
Now,
A/B=sin(2x)/sinh(2y)
If any questions, let me know.
The 10-kg lamp is suspended from the
three equal-length cords. Determine its
smallest vertical distance s from the
ceiling if the force developed in any
cord is not allowed to exceed 50 N.
120°
A
600 mm
120°
Answer:
hello your question is incomplete attached below is the complete diagram
answer : 519 mm
Explanation:
Given the conditions it can be said that the cords are symmetric i.e. AD, BD , CD has same value
hence ; DA = DB = DC = 600 mm
Tension in all cords are the same ( T ) = 50 N
lets assume the angle between the cords and the Z-axis is ∅
∑ Fz = 0
3 * T cos ∅ - 10*9.81 = 0
therefore ; ∅ = 49.16°
looking at attached triangle AD0
tan ∅ = [tex]\frac{600}{s}[/tex]
Hence ; s = 519 mm
What can firefighters do to reduce the risk to people living in Skyview?
Answer:
The City can grant higher budgets to emergency services like the Fire Department, so a higher budget will allow engineers & scientists to innovate new technology and add more fire stations across the city.
Explanation:
Steam enters a heavily insulated throttling valve at 11 MPa, 600°C and exits at 5.5 MPa. Determine the final temperature of the steam.
Answer: the final temperature of the steam 581.5 °C
Explanation:
Given that;
P₁ = 11 MPa
T₁ = 600°C
exit at; P₂= 5.5 MPa
Now from superheated steam table( p=11 MPa, T=600°C)
h₁ = 3615 kJ/kg
h₁ = h₂ ( by throttling process and adiabatic isentholpic )
from saturated steam table at; ( h= 3615 kJ/kg, P= 5.5 MPa )
Temperature = 581.5 °C
Therefore the final temperature of the steam 581.5 °C
Before finishing and installing a shelved cabinet you just constructed, you need to check the
nside corners for 90 degree angles. Which hand tool would meet the needs of this task?
Answer:
Carpenter's square
Explanation:
The most common hand tool used to measure or set angles with its application extending to setting angles of roofs and rafters. Another name of a Carpenter's square is a framing square.
Other hand tools that are used to measure angles are;
The combination square that allows a user to set both 90° and 45° anglesA Bevel that allows users to set any angle they like.A Protractor that resembles a bevel but its marks are marked in an arc.An electromagnetic angle finder which gives a reading according to the measure of the arms adjusted by the user.Watch for signs that your vehicle is actually ________ by other drivers.
Answer:
Seen
Explanation:
The correct answer to the given question is Seen
The complete sentence is:
Watch for signals that your vehicle is actually seen by other drivers.
This is the correct answer and completes the sentence given in the question.
The blank area is to be filled with the word Seen which will complete the sentence.
A 2x10 wood beam is to support a service dead load (including beam self-weight) of 50 lbs/ft and a service live load of 60 lbs/ft (note that the loads given are per foot and not per square ft). The beam is part of a series of adjacent parallel beams spaced 16 inches apart. Span length is 15 ft. Assume that lateral buckling is prevented. Wood species/grade is "Red Maple", No.1. Moisture content is less than 19% (dry). This member’s service temperature is not elevated. What is the design moment strength (M'n) in kip-in?
Answer:
The answer is "[tex]30.83 \ kip-in[/tex]"
Explanation:
[tex]\to D.L = 50 \ \frac{ lbs}{ft} \\\\\to L.L = 60\ \frac{ lbs}{ft}\\\\[/tex]
Factered load [tex]w_u= 1.2 D.L+1.6 \ D.L[/tex]
[tex]= 1.2 \times 50 +1.6\times 60\\\\= 60 +96\\\\=156 \ \frac{ lbs}{ft}\\\\= 131 \frac{ lbs}{in}\\\\[/tex]
[tex]A= bd= 2\times 10 = 20 \ in^2\\\\Z= \frac{bd^2}{6} =\frac{2\times10^2}{6}= 33.33 \ in^3 \\\\L= 15 \ ft = 180 \ inch[/tex]
bending strength[tex]= f_b =925 \ psi[/tex]
shear strength[tex]= f_v = 120 \ psi[/tex]
movment strength [tex]m_h= z \times f_b[/tex]
[tex]= 33.33 \times 925\\\\ = 20830.25 \ lb-in \\\\ = 30.83 \ kip-in[/tex]
If electrons have a path to follow, they will flow to a area with charge
Answer:
Hello there, the question is not complete, but not to worry you can check the explanation section to check how you can solve a similar question or to be be able to solve the exact question directly.
Explanation:
The flow of electrons is what is known or refer to as Current. When energy is used on a nuclei, the electrons are forced to move from one position to the other. The direction of flow of electron is from the negative terminal which then moves to the positive terminal.
Therefore, it can be said that the positive charge determines the direction of electron flow. The starting point is the negative terminal, in which it will now move in the direction in which the positive terminal is.
What dimensioning error is shown in this drawing?
At 1 atm, nitrogen (N2) molecules become a liquid below 77 K. Thus the vapor pressure of liquid nitrogen is 1 atm at 77 K. Use this information to estimate the binding energy of a nitrogen molecule within the liquid. Note: You may assume that the equilibrium condition for this system is NG/V = nre-A/KT', with ny =1.93 x 1031 m-3, and that the nitrogen gas is ideal.
a. 0.081 eV
b. 81 eV
c. 0.0081 eV
d. 0.81 eV
e. 8.1 eV
There are four main exit strategies for ending your involvement with a company: selling the company, liquidating the company by selling assets and releasing the cash flow to investors, selling stock to the public, or selling private stock to private investors. Which exit plan strategy will you choose for your company? Explain why
6.A tape measure is used
A. in manufacturing industries
B. in construction industries
C. for precision measurement
D. A and B
An aggregate blend is composed of 55% aggregate A (Sp. Gr. 2.631), 25% aggregate B (Sp. Gr. 2.331) and 20% sand (Sp. Gr. 2.609). The Sp. Gr. of the blend aggregate is most nearly:_______
a. 2.732
b. 2.545
c. 2.581
d. 2.614
Answer:
The right choice would be Option b (2.545).
Explanation:
The given values are:
The aggregate blend will be:
[tex]W_A[/tex] = 55%
[tex]G_ A[/tex] = 2.631
[tex]W_ B[/tex] = 25%
[tex]G_B[/tex] = 2.331
[tex]W_C[/tex] = 20%
[tex]G_C[/tex] = 2.609
Now,
On applying the formula, we get
⇒ [tex]G_{BA}=\frac{W_A+W_B+W_C}{\frac{W_A}{G_A} +\frac{W_B}{G_B} +\frac{W_C}{G_C}}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{55+25+20}{\frac{55}{2.631} +\frac{25}{2.331} +\frac{20}{2.609}}[/tex]
⇒ [tex]= \frac{100}{\frac{55}{2.631} +\frac{25}{2.331} +\frac{20}{2.609}}[/tex]
⇒ [tex]=2.545[/tex]
What is substructure work?
O Work above ground level
Work on ground level
O Work below ground level
O Work above the superstructure
Type the correct answer in the box. Spell all words correctly. Ronny wants to calculate the mechanical advantage. He needs to determine the length of the effort arm and the length of the load arm. How can he find the length of the effort arm? The length of the effort arm is the distance between the _____ and the point at which effort is applied.
Answer:
Fulcrum
Explanation:
The length of the effort arm is the distance between the Fulcrum and the point at which effort is applied.
Mechanical advantage is a measure of the ratio of output force to input force in a system, used to analyze the forces in simple machines like levers and pulleys. Despite changing the forces that are applied the conservation of energy is still true and the output energy is still equal to the input energy. Typically the mechanical advantage is expressed in ideal terms, where there is no losses in energy between the input and output times, also known as 100% efficient systems.
By conservation of energy:
Fi×di=Fo×do
A household oven door of 0.6-m height and 0.7-m width reaches an average surface temperature of 32°C during operation. The temperature of ambient air is 22°C. Assuming the door has an emissivity of 0.4 and the surroundings are also at 22°C, determine the heat transfer by free convection and the heat transfer by radiation.
Answer:
a) ≈ 11.7 watts
b) ≈ 21.4 watts
Explanation:
Given data :
Oven door dimensions : 0.6m by 0.7m
average surface temperature = 32°c
Temperature of ambient air = 22°c
emissivity of door = 0.4
surrounding temperature = 22°c
a) Calculate heat transfer by free convection
q = 3.34 ( 0.5 * 0.7 ) (32-22 ) ≈ 11.7 watts
attached below is the detailed solution
b) calculate heat transfer by radiation
q = ∈.As б ( Ts^4 - Tsun^4 )
= 1( 0.5*0.7 ) * 5.67 * 10^-8 [( 273+32)^4 - ( 273+22)^4 ]
≈ 21.4 watts
You are provided with the projected income statements for a project: Year 1 2 3 4 Revenues ( MUR '000) 10,000 11,000 12,000 13,000 Less Cost of Goods Sold ( MUR '000) 4,000 4,400 4,800 5,200 Less Depreciation ( MUR '000) 4,000 3,000 2,000 1,000 Earnings Before Interest and Tax ( MUR '000) 2,000 3,600 5,200 6,800 The tax rate is 40%. The project requires an initial investment of MUR 15 million and an additional MUR 2 million at the end of year 2. The working capital is anticipated to be 10% of revenues and the working capital investment has to be made at the beginning of each period. Estimate the free cash to the firm for each of the 4 years, the payback period for investors in the firm, and the net present value if the cost of capital is 12 %? Would you accept the project?
Answer:
a. Free cash to the firm:
Year 1 2 3 4
Free Cash Flow to the firm ( MUR '000) 3,708 3,542 3,506 3,470
b. The payback period for this project, based on the free cash flow, is after year 4.
c. The net present value is (MUR 5,757,000)
d. No. Based on the payback period and the net present value, the project should be rejected.
Explanation:
a) Data and Calculations:
Projected Income Statements
Year 1 2 3 4
Revenues ( MUR '000) 10,000 11,000 12,000 13,000
Less Cost of Goods Sold ( MUR '000) 4,000 4,400 4,800 5,200
Less Depreciation ( MUR '000) 4,000 3,000 2,000 1,000 Earnings b/4 Interest & Tax ( MUR '000) 2,000 3,600 5,200 6,800
Interest on capital (12%) ( MUR '000) 1,800 2,040 2,040 2,040
Earnings before tax ( MUR '000) 200 1,560 3,160 4,760
Income Tax (40%) 80 624 1,264 1,904
Net Income after tax ( MUR '000) 120 936 1,896 2,856
Add Depreciation ( MUR '000) 4,000 3,000 2,000 1,000
Net cash from operations (MUR '000) 4,120 3,936 3,896 3,856
Working capital investment (MUR '000) 412 394 390 386
Free Cash Flow to the firm 3,708 3,542 3,506 3,470 Net present value
The payback period for this project, based on the free cash flow, is after year 4.
Interest on capital:
Initial investment = MUR 15 million * 12% = MUR 1,800,000 for year 1
Additional investment = MUR 2 million * 12$ = 240,000
Total interest expense from year 2 = MUR 2,040,000
Net present value:
Year 1 2 3 4 Total
Free Cash Flow to the firm 3,708 3,542 3,506 3,470 14,226
Discount factor 0.893 0.797 0.712 0.636
Present value 3,311 2,823 2,496 2,207 10,837
Cash outflows: 15,000 1,594 0 0 16,594
Net present value = (5,757)
Cash outflow for year 2 = 2,000,000 * 0.797 = 1,594,000
