Answer:
While scientists study how nature works, engineers create new things, such as products, websites, environments, and experiences. Because engineers and scientists have different objectives, they follow different processes in their work.
Explanation:
The displacement volume of an internal combustion engine is 3 liters. The processes within each cylinder of the engine are modeled as an air-standard Diesel cycle with a cutoff ratio of 2.5. The state of the air at the beginning of compression is fixed by P1=95kPa, T1=22oC, and V1 = 3.17 liters.
Determine the net work per cycle, in kJ, the power developed by the engine, in kW, and the thermal efficiency, if the cycle is executed 1000 times per min.
Answer:
1) The power developed by the engine is 14705.7739 kW
2) The thermal efficiency is approximately 61.5%
Explanation:
The given parameters are;
P₁ = 95 kPa
T₁ = 22°C
V₁ = 3.17 liters
The cutoff ratio = 2.5
Displacement volume = 3 liters
The number of times the cycle is executed per minute = 1000 times per minute
We have;
The displacement volume = V₁ - V₂ = 3 l
V₁ = 3.17 l
V₂ = 3 - 3.17 = 0.17 l
Compression ratio = V₁/V₂ = 3.17/0.17 ≈ 18.65
P₂/P₁ = P₂/(95 kPa) = (V₁/V₂)^(k) = 18.65^1.4
P₂ = (95×18.65^(1.4)) ≈ 5710.5 kPa
T₂/T₁ = (V₁/V₂)^(k - 1)
T₂/(295 K)= (18.65)^(1.4 - 1)
T₂ = 295 * (18.65)^(1.4 - 1) = 950.81 K
The cutoff ratio = V₃/V₂ = 2.5
T₃ = T₂ × V₃/V₂ = 2.5 * 950.81 K = 2377.025 K
[tex]Q_{in}[/tex] = [tex]C_p[/tex]×(T₃ - T₂) = 1.006 × (2377.025 - 950.81) = 1,434.77 kJ/kg
T₄ = T₃ × (V₃/V₄)^(k-1) =
Therefore,
[tex]T_4 = T_3 \times \left (\dfrac{r_c}{r} \right )^{k - 1} = 2377.025 \times \left( \dfrac{2.5}{18.65} \right )^{1.4 - 1} \approx 1064 \ K[/tex]
T₄ ≈ 1064 K
[tex]Q_{out}[/tex] = [tex]-C_v \times (T_4 - T_1)[/tex]
[tex]C_v = C_p/k = 1.006/1.4 \approx 0.7186 \ kJ/kg[/tex]
∴ [tex]Q_{out}[/tex] = 0.7186×(1064 - 295) = 552.6034 kJ/kg
1) The net work = [tex]Q_{in}[/tex] - [tex]Q_{out}[/tex] = 1,434.77 kJ/kg - 552.6034 kJ/kg ≈ 882.17 kJ/kg
The number of cycle per minute = 1000 rpm
The number of cycle per minute = 1000 rpm/60 = 16.67 cycles per second
The power developed by the engine = The number of cycles per second × The net work of the engine
Therefore;
The power developed by the engine = 16.67 cycles/second × 882.17 kJ/kg
The power developed by the engine = 14705.7739 kW
2) Efficiency, [tex]\eta _{th}[/tex], is given as follows;
[tex]\eta _{th} = \dfrac{Q_{in}-Q_{out}}{Q_{in}} \times 100 = 1 - \dfrac{Q_{out}}{Q_{in}} \times 100= 1 - \dfrac{552.6034}{1434.77}\times 100 \approx 61.5\%[/tex]
Therefore, the thermal efficiency ≈ 61.5%.
i need solution for this question please
Select the right answer
Explanation:
the 7th one answer is beacause mercury is bad at sharing electrons
the 8th one's answer is Rhodium
Answer:
1.E aluminum
2.E all
3. Either d or e leaning to e
A boiler is designed to work at 14bar and evaporate 8 kg/s of water. The inlet water to the boiler has a temperature of 400C and at exit the steam is 0.95 dry. The flow velocity at inlet is 10 m/s and at exit 5 m/s and the exit is % m above the elevation at entrance. Determine the quantity of heat required. What is the significance of changes in kinetic and potential energy on the result.
Answer:
Explanation: 2 is thy answer
Which of the following was an effect of world war 2 on agricultural industry
Answer:
Option C..Farmers saught new technology to help with the workload
hope this helped you
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You have a piece of film paper that is 3 in x 5 in. You fix it inside the back of a pinhole camera with a focal length of 5.5 in. You want to use it to take a picture of your team’s mascot – a giant guinea pig that just barely fits in a 4 ft. tall cube. The picture will be taken directly in front, from a stool that places the aperture 2 ft. above the ground. You have to determine how far away the camera must be from your mascot to get a good portrait that fills up the whole film paper, without cutting any part of him off. How far apart should the camera and the mascot be to take the portrait? Show your work.
Answer:
In order to take a portrait, the distance of the mascot from the camera should be approximately 7.33 feet
Explanation:
The size of the film paper = 3 in. × 5 in.
The focal length of the camera = 5.5 in.
The height and width of the guinea pig = 4 ft.
The height of the aperture above the ground = 2 ft.
Therefore, we have;
Magnification = Height of image/(Height of object)
Withe the 3 in. wide film, we have;
Magnification = 3 in./(4 ft.) = 3 in./(48 in.) = 0.0625
Magnification = Length of camera/(Distance of object from pin hole)
∴ Length of camera/(Distance of object from pin hole) = 0.0625
Length of camera = Focal length of the camera = 5.5 in.
Therefore;
5.5 in./(Distance of object from pin hole) = 0.0625
Distance of object from pin hole = 5.5/0.0625 = 88 inches = 7.33 ft
Therefore, the camera should be approximately 7.33 ft. from the mascot to take a portrait.
In this exercise we have to use the magnification knowledge to calculate the distance that the photograph should be taken, thus we have to:
Distance of the mascot from the camera should be approximately 7.33 feet
To calculate the best distance to take the photo, we have that some information must be taken into account such as:
Size of the film paper: [tex](3)*(5) in[/tex] Focal length of the camera: [tex]5.5 in[/tex] Height and width of the guinea pig: [tex]4 ft[/tex] Height of the aperture above the ground: [tex]2 ft[/tex]
Therefore, we have that the formula of magnification is:
[tex]Magnification = Height \ of \ image/(Height \ of \ object)[/tex]
With the 3 in wide film, we have;
[tex]Magnification = 3 in/(4 ft) \\= 3 in/(48 in) = 0.0625 in[/tex]
Rewriting the magnification formula as:
[tex]Magnification = Length \ of \ camera/(Distance \ of \ object \ from \ pin \ hole)[/tex]
Substituting the values already known we have the equation will be matched as:
[tex]Length\ of \ camera/(Distance\ of\ object \ from \ pin \ hole) = 0.0625\\Length \ of \ camera = Focal \ length \ of \ the \ camera = 5.5 in.[/tex]
Therefore;
[tex]5.5 /(Distance \ of \ object\ from \ pin\ hole) = 0.0625 in\\Distance \ of \ object\ from \ pin \ hole = 5.5/0.0625\\ = 88 inches = 7.33 ft[/tex]
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Transmission lines that join two Balancing Authority Areas are known as
Milton has been tracking the migrating patterns of whales in the northwest Atlantic Ocean for five years. He knows where and when to find them as well as how quickly they move. Which qualification makes Milton successful in his research?
Answer:
knowledge of animal behavior and anatomy
Explanation:
the qualification that will make Milton successful in his research is a knowledge of animal behaviour and also their anatomy. the knowledge of whales behaviour has opened his eyes into their world so he knows to a great deal about them. it is through his knowledge of the behaviour of whales that he's able to get used to their migrating patterns to know where and when to find them. Also, through the body anatomy of whales he knows what their movement is like.
Answer:
knowledge of animal behavior and anatomy
You are designing an airplane to carry liquid cargo that will slosh and move side to side in its container. This could make the plane unstable. What type of airfoil would you use for the wing? Why. Answer in a full sentence or more
how do you make coke for steel?
A tensile test uses a test specimen that has a gage length of 50 mm and an area = 206 mm2. During the test, the specimen yields under a load of 97,944 N. The corresponding gage length = 50.2 mm - this is at the 0.2 percent yield point. The maximum load of 162,699 N is reached at a gage length = 63 mm. If fracture occurs at a gage length of 71 mm, determine the percent elongation in % - enter your answer as a whole number, not as a fraction.
Answer:
The percent elongation in the length of the specimen is 42%
Explanation:
Given that:
The gage length of the original test specimen [tex]L_o[/tex] = 50 mm
The final gage length [tex]L_f[/tex] = 71 mm
The area = 206 mm²
maximum load = 162,699 N
To determine the percent elongation in %, we use the formula:
[tex]\%EL = \dfrac{L_f-L_o}{L_o}\times 100[/tex]
[tex]\%EL = \dfrac{71 \ mm-50 \ mm}{50 \ mm}\times 100[/tex]
[tex]\%EL = \dfrac{21 mm}{50 \ mm}\times 100[/tex]
[tex]\%EL = 0.42 \times 100[/tex]
[tex]\mathbf{\%EL = 42 \%}[/tex]
The percent elongation in the length of the specimen is 42%
Key length is designed to provide desired factor of safety
a. True
b. False
Answer: true
Explanation:
A key is a machine element that us used to connect the element of a rotating machine to a shaft. It should be noted that the key hinders the relative rotation that may take place between the two parts.
Key length is designed to provide desired factor of safety. It should also be noted that the factor of safety shouldn't be much and the key length is typically limited to the hub length.
What is the capacity of the machine in batches?
What are the common approximations made in the analysis of heat exchangers?
Answer: making sure that they are up to date
Explanation:
What is the transfer of energy from one object to another?
Answer:
Kinetic Energy
Explanation:
Energy is transferred from one object to another when a reaction occurs. Energy can be transferred from one object to another as heat, light, and motion.
what type of diagrams can you create using a compass, a T-square, a triangle, and a protractor?
Answer:
15
Explanation:
A compass may be used to create circles, arcs, bisect lines, angle bisectors, and locate midpoints. By using a compass, a protector is also drawn.
What is the compass?A compass, or more correctly, a pair of compasses, is a tool for technical drawing that may be used to draw arcs or circles. It can also be used as dividers to indicate distances, particularly on maps.
A compass, or more correctly, a pair of compasses, is a tool for technical drawing that may be used to draw arcs or circles. It may also be used as dividers to indicate distances, particularly on maps. Compasses can be used for navigation, mathematics, and other things.
Therefore, a protector is sketched using a compass.
Learn more about the compass, refer to:
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12. You need to be at the lift controls whenever the lift is in motion A) True B)False
the answer to that would be a) true
While out on the International Space Station, an engineer was able to gather a sample of a new type of unidentified rock. What knowledge will the engineer use to predict the potential of this new material?
Answer:
The engineer will conduct a variety of tests, including chemical, mechanical, electrical, and physical examinations, to determine the potential of the new material.
Explanation:
They will need to test the material, this will also help to determine its malleability.
Hope this helps!
How can you safely lift and support a vehicle
Answer:
Place the jack under the part of the vehicle that it should contact when raised. If you're using jack stands, place them near the jack. If you place your jack incorrectly, you can injure your car. To find the proper place to position the jack for your particular vehicle, check your owner's manual.
The easiest way to reduce your exposure to dangerous fumes is to keep your head out of a fume plume, making sure that you're breathing the cleanest air possible.
Answer:
keep your head out of a fume plume
Explanation:
According to the guidelines and precaution procedures of OSHA, an acronym for Occupational Safety and Health Administration in the United States of America stated that The easiest way for an individual to reduce his or her exposure to dangerous fumes is to ensure that such person keeps his or her head out of a fume plume.
Hence, in this situation, the correct answer is "keep your head out of a fume plume"
Two wooden members of uniform rectangular cross section are joined using a simple glued scarf splice. The maximum allowable shearing stress and maximum allowable normal stress in the glued splice is 50 MPa and 100 MPa, respectively. The cross-section area of the glued member is 400 mm2. (a) What should the value of the angle be to achieve maximum load Fmax? (b) What is the magnitude of the maximum load Fmax?
Answer:
a). α = 26.57
b). Maximum load is 50 .kN
Explanation:
a).
The normal force is given by
N = σ A cosec β
where, σ is the normal stress
A is the cross sectional area
Similarly, shear force is given by
S= τ A cosec β
where, τ is the shearing stress
Now from the figure,
tan β = S/N
= τ/σ
Therefore, [tex]$\beta = \tan^{-1}(2)$[/tex] = 63.43
α = 90 - β = 26.57
b).
The normal force is given by
[tex]$N=(100\times 10^6)(400\times 10^{-6}) \text{ cosec}\ 63.43$[/tex]
[tex]$N=44.78\times 10^3$[/tex] N
We have
[tex]$\Sigma F_y=0$[/tex]
∴ N - F sin β = 0
⇒ F = N / sin β
= [tex]$\frac{44.72\times 10^3}{\sin(63.43)} = 50\times 10^3 N$[/tex]
Similarly,
The shear force is given by
S = τ A cosec β
= [tex]$(50\times 10^6)(400\times 10^{-6}) \text{ cosec}\ 63.43 = 22.36\times 10^3 N$[/tex]
[tex]$\Sigma F_x=0$[/tex]
∴ S - F cos β = 0
⇒ F = S / cos β
[tex]$\frac{22.36\times 10^3}{\cos(63.43)} = 49.99\times 10^3 N$[/tex]
Therefore, force is 50 kN.
An input voltage of 9.2 V is to be converted into its digital counterpart using an analog-to digital converter. The voltage range is 0 to 16 V. The ADC has 4-bit capacity. Determine: (a) What are the number of quantization levels, resolution, and the maximum quantization error of this ADC
Answer:
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In an intrinsic semiconductor, the number of free electrons is equal to what?
Answer:
The number of holes.
Explanation:
A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;
1. Extrinsic semiconductor.
2. Intrinsic semiconductor.
An intrinsic semiconductor is a crystalline solid substance that is in its purest form and having no impurities added to it. Examples of intrinsic semiconductor are Germanium and Silicon.
In an intrinsic semiconductor, the number of free electrons is equal to the number of holes. Also, in an intrinsic semiconductor the number of holes and free electrons is directly proportional to the temperature; as the temperature increases, the number of holes and free electrons increases and vice-versa.
In an intrinsic semiconductor, each free electrons (valence electrons) produces a covalent bond.
Which statement demonstrates the most scientific observation?
What are materials engineers trying to discover when they study different materials? Whether or not materials corrode and oxidize how materials perform and deteriorate if certain materials have been used in the past and at which historical ages which metals conduct heat
Answer:
Material engineers study various materials to discover the reason and cause of its existence, the chemical properties, how long it has been there, and how it impacts human life.
Explanation:
Material engineer is an engineering discipline that focuses to improve human life by studying the environment and the various elements or materials it holds.
It uses the power of pure science to test and analysis its findings, documents its features and exposes them to the world. Materials like metals and other elemental forms were all tested by these engineers to determine its history and chemical and biological use.
Answer:
how materials perform and deteriorate
Explanation:
What allows negative feedback to control a system
Answer:
Negative feedback control of the amplifier is achieved by applying a small part of the output voltage signal at Vout back to the inverting ( – ) input terminal via the feedback resistor
Answer:
The system has parts that sense the amount of output
Explanation:
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Block B has a mass of 27g and a density of 0.9 g/mL. What is the volume of block B? Will it float in water? (density of water is 1.0 g/mL) Don't forget the units.
Help me for this question
What is the period if the clock frequency is 3.5 GHz?
Answer:
Period = 0.2857 nanoseconds
Explanation:
We are told that frequency = 3.5 GHz
This is simply 3.5 × 10^(9) Hz
Now, from wave equations, Period is given by the formula;
Period = 1/frequency
Thus;
Period = 1/(3.5 × 10^(9))
Period = 0.2857 × 10^(-9) seconds
From conversions, we can simplify the answer.
1 second = 10^(-9) nanoseconds
Thus, 0.2857 × 10^(-9) seconds = 0.2857 × 10^(-9) × 10^(-9) nanoseconds = 0.2857 nanoseconds
Wheel grinders need be equipped with an
Answer:
wheel guard
Explanation:
to protect our hands and reduce spark
What do we need to build a car?