Answer:
A) Rate of heat addition = 228.53 Hp
B) Maximum Air temperature = 1109 °C
Explanation:
We are given;
Cut off ratio; r_c = 1.5
Compression ratio; r = 18
Power produced; W` = 150 Hp
cp = 1.005 kJ/kg·K
cv = 0.718 kJ/kg·K
R = 0.287 kJ/kg·K
k = 1.4
Temperature;T1 = 17°C = 17 + 273 K = 290K
I've attached the rest of the explanation below.
Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. Provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20 ℃ throughout the year, while the walls of the room are nominally at 27 ℃ and 14 ℃ in the summer and winter, respectively. The exposed surface of a person in the room may be assumed to be at a temperature of 32 ℃ throughout the year and to have an emissivity of 0.90. The coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 W/m2∙K.
Answer:
radiative heat loss substantially increases as the wall temperature declines
Explanation:
The body's heat loss due to convection is ...
(2 W/m^2·K)((32 -20)K) = 24 W/m^2
__
The body's heat loss due to radiation in the summer is ...
[tex]\epsilon\sigma(T_b^4-T_w^4)\quad\text{where $T_b$ and $T_w$ are body and wall temperatures ($^\circ$K)}\\\\0.90\cdot 5.6703\cdot 10^{-8}(305.15^4-300.15^4)\,\text{W/m$^2$}\\\\\approx 28.3\,\text{W/m$^2$}[/tex]
The corresponding heat loss in the winter is ...
[tex]0.90\cdot 5.6703\cdot 10^{-8}(305.15^4-287.15^4)\,\text{W/m$^2$}\\\\\approx 95.5\,\text{W/m$^2$}[/tex]
Then the total of body heat losses to surroundings from convection and radiation are ...
summer: 24 +28.3 = 52.3 . . . W/m^2
winter: 24 +95.5 = 119.5 . . . W/m^2
__
It is reasonable that a person would feel chilled in the winter due to the additional radiative loss to the walls in the winter time. Total heat loss is more than doubled as the wall temperature declines.
Which greenhouse gas is produced by commercial refrigeration and air conditioning systems?
carbon dioxide
Ofluorinated gas
O nitrous oxide
O methane
Answer:
B- Fluorinated gas
Explanation:
Answer:
B.) fluorinated gas
Explanation:
A piston cylinder device contains 5 kg of Refrigerant 134a at 600 kPa and 80 C. The refrigerant is now cooled at constant pressure until it reaches a liquid-vapor mixture state with a quality of 0.3. How much heat was extracted in the process?
Answer:
The answer is 920 kJ
Explanation:
Solution
Given that:
Mass = 5kg
Pressure = 600 kPa
Temperature = 80° C
Liquid vapor mixture state (quality) = 0.3
Now we find out the amount of heat extracted in the process
Thus
Properties of RI34a at:
P₁ = 600 kPa
T₁ = 80° C
h₁ = 320 kJ/kg
So,
P₁ = P₂ = 600 kPa
X₂ =0.3
h₂ = 136 kJ/kg
Now
The heat removed Q = m(h₁ -h₂)
Q = 5 (320 - 136)
Q= 5 (184)
Q = 920 kJ
Therefore the amount of heat extracted in the process is 920 kJ
A refrigerator with an average cop of 2.8 used to cool a well-insulated container whose contents are equivalent to 10 kg of water, from 40'C to 10'C. The refrigerator consumes 400 W of electric power. Considering the specific heat of water as 4.2 kj/kgC, the time required to cool the water is ? my answer is 19 min.is it true ?
Answer:
Yes, it is true
Explanation:
The computation of the time required to cool the water is shown below:
GIven that
Average cop = 2.8
Therefore the cooling effect is
= 2.8 × 400 W
= 1,120 W
ANd, the specific heat of water is 4.2 kj/kg°C i.e 4,200 j/kg°C
Now we assume the time is t
As we know that
[tex]1,120 \times t = 10\times 4,200 \times (40 - 10)\\\\ therefore\\\\ t = \frac{10\times4,200\times30}{1,120}[/tex]
t = 1,125 seconds
So, it would be 19 minutes
Therefore it is true
Describe the components of a stream's load and how is each component is transported. Discuss at least two factors that affect the transportation of the load and evaluate the impact of each on components of a stream load.
Answer:
zsxdcffffusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernameusernamev
Explanation:
What is the criteria for a guard having to be used on a machine?
The criteria for a guard having to be used on a machine is;
As a safety measure If the operation exposes you to an injury.
When operating a machine, there are possibilities that the operator could be injured or exposed to injury.
Due to the possible safety issues when operating a machine, the Occupational Safety and Health Administration (OSHA) in their 29 code mandated that a safeguard must be put at each machine to ensure that there is adequate safety that prevents or minimizes the risk of getting injured.
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A typical discounted price of a AAA battery is $0.75. It is designed to provide 1.5 volts and 1.0 amps for about an hour. Now we multiply volts and amps to obtain power of 1.5 watts from the battery. Thus, it costs $0.75 for 1.5 Watt-hours of energy. How much would it cost to deliver one kilo Watt-hour? How does this compare with the cost of energy from your local electric utility at $0.10 per kilo Watt-hour?
Answer:
gh fjh,vx j ahj ds djv dk
Explanation:
doing for points
The Cost of 1 kilowatt hour of energy at the rate of $0.75 per 1.5 watt hour is $500 which is 5000 times greater than the cost of energy at $0.10 per kilowatt hour.
Battery power = Current × Voltage
Cost of 1.5 Watt-hour = $0.75
Converting Energy to Watt - hour :
1 kilowatt = 1000 watt
1 kilowatt hour = 1000 watt - hour
Hence,
Cost of 1 kilowatt - hour = 1000 watt - hour can be calculated thus :
1.5 Watt-hour = $0.75
1000 Watt-hour = c
Cross multiply :
1.5c = $0.75 × 1000
1.5c = 750
c = 750 / 1.5
c = 500
Therefore, cost of 1 kilowatt - hour of energy will be $500
Comparing the cost of Energy at $500 per Kilo-Watt hour to Cost at $0.10:
$500 / $0.10 = 5000
Therefore, the cost of energy at $500 per kilowatt hour is 5000 times greater than cost at $0.10 per kilowatt hour.
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Technician A says powdered metal rods can be resized just like a regular rod. Technician B says powdered metal rods can be resized if bearings of a larger diameter are available for that particular engine. Who is correct?
Answer:
Technician B is correct
Explanation:
To resize a connecting rod’s big end, the bolts are removed and the cap and rod mating surfaces will be ground to an approximate measurement. Thereafter, the rod cap will be bolted back onto the rod while the bore is machined back to it's proper size. However, the challenge with powdered metal rods is that due to the fact that the fractured surface is critical to their alignment, they cannot tolerate having those surfaces ground smooth. Hence, they cannot be resized, except bearing inserts of larger diameters are available for that particular engine.
Thus, technician B is correct.
Tech A says that a gear set that has a drive gear with 9 teeth and a driven gear with 27 teeth has a gear ratio of 3:1. Tech B says that the drive gear is also called the output gear. Who is correct?
Answer:
Tech A is correct.
Explanation:
Gears are toothed wheels that can be used to transmit power. When two or more gears are in tandem, a gear train is formed.
Gear ratio = [tex]\frac{number of teeth of the driven gear}{Number of teeth of the driving gear}[/tex]
= [tex]\frac{27}{9}[/tex]
= [tex]\frac{3}{1}[/tex]
Gear ratio = 3:1
The driver gear is called the input gear since it transfers its power to the driven gear. While the driven gear is called the output gear because it produces an effect due to both gears.
Tech A is correct.
A rectangular steel bar 37.5 mm wide and 50 mm thick is pinned at each end and subjected to axial compression. The bar has a length of 1.75 m. The modulus of elasticity is 200 Gpa. What is the critical buckling load
Answer:
The critical buckling load is [tex]\mathbf{P_o = 141.61 \ kN}[/tex]
Explanation:
Given that:
the width of the rectangular steel = 37.5 mm = 0.0375 m
the thickness = 50 mm = 0.05 m
the length = 1.75 m
modulus of elasticity = 200 Gpa = 200 10⁹ × Mpa
We are to calculate the critical buckling load [tex]P_o[/tex]
Using the formula:
[tex]P_o = \dfrac{\pi ^2 E I}{L^2}[/tex]
where;
[tex]I = \dfrac{0.0375^3*0.05}{12}[/tex]
[tex]I = 2.197 * 10^{-7}[/tex]
[tex]P_o = \dfrac{\pi ^2 *200*10^9 * 2.197*10^{-7}}{1.75^2}[/tex]
[tex]P_o = 141606.66 \ N[/tex]
[tex]\mathbf{P_o = 141.61 \ kN}[/tex]
The critical buckling load is [tex]\mathbf{P_o = 141.61 \ kN}[/tex]
what is the difference between erratic error and zero error
The negative mark is balanced by a positive mark on the set key scale while the jaws are closed.
It is common practice to shut the jaws or faces of the system before taking some reading to guarantee a zero reading. If not, please take care of the read. This read is referred to as "zero defect."
There are two forms of zero error:
zero-mistake positive; and
Non-null mistake.
----------------------------
Hope this helps!
Brainliest would be great!
----------------------------
With all care,
07x12!
When checking the resistance of a dual voltage wye motor, there should be ____ resistance readings. 1) twelve 2) six 3) three
Answer:
1) twelve
Explanation:
The dual voltage motors are used in day to day operations. The wye is connected with 9 lead motors. Maximum resistance can be obtained if the resistance are connected in series. To check resistance of dual voltage wye motor there must be twelve resistance readings of 1 ohm each.
Technician A says that the micrometer operates on a simple principle: The spindle has 20 threads per inch, so one revolution of the thimble will advance or retract the spindle 1/20 of an inch. Technician B says that spindle has 50 threads per inch, so one revolution of the thimble will advance or retract the spindle 1/50 of an inch. Who is correct
Answer:
Explanation:
neither of the technicians is correct
A gold vault has 3 locks with a key for each lock. Key A is owned by the
manager whilst Key B and C are in the custody of the senior bank teller
and the trainee bank teller respectively. In order to open the vault door at
least two people must insert their keys into the assigned locks at the same
time. The trainee bank teller can only open the vault when the bank
manager is present in the opening.
i) Determine the truth table for such a digital locking system (4 marks)
ii) Derive and minimize the SOP expression for the digital locking system
Answer:
see the attached truth tableOpens = AB + ACExplanation:
i) In the attached truth table, TRUE means the respective key owner is present and their keys are inserted at the same time. The "Opens" column is TRUE when two owners are present, not including the case where the only two owners present are B and C.
__
ii) The second attachment is a Karnaugh map of the truth table. The circled terms are ...
Opens = AB +AC
how does a TV'S screen work
Answer:
A TVS screen works when the pixels are switched on electronically using liquid crystals to rotate polarized light.
Explanation:
Determine the combined moment about O due to the weight of the mailbox and the cross member AB. The mailbox weighs 3.2 lb and the uniform cross member weighs 10.3 lb. Both weights act at the geometric centers of the respective items. The moment will be positive if counterclockwise, negative if clockwise.
Answer:
Attached is the complete question but the weight of the mailbox and cross bar differs from the given values which are : weight of mail box = 3.2 Ib, weight of the uniform cross member = 10.3 Ib
Answer : moment of inertia = 186.7 Ib - in
Explanation:
Given data
weight of the mailbox = 3.2 Ib
weight of the uniform cross member = 10.3 Ib
The origin is of mailbox and cross member is 0
The perpendicular distance from Y axis of centroid of the mailbox
= 4 + (25/2) = 16.5"
The centroid of the bar =( ( 1 + 25 + 4 + 4 ) / 2 ) - 4 = 13"
therefore The moment of Inertia( Mo) = (3.2 * 16.5) + ( 10.3 * 13)
= 52.8 + 133.9 = 186.7 Ib-in
The combined moment about O due to the weight of the mailbox and the cross member AB is; M_o = 122.4 lb.in (ccw)
We are given;
Weight of mailbox; W_m = 3.2 lb
Weight of uniform cross member; W_c = 10.3 lb
Now, from the attached diagram, let us calculate the geometric location of the mailbox and uniform cross section from point O.
Geometric location of mailbox from point O; g_m = 3 + (19/2) = 12.5 in
Geometric location of cross member from point O;
g_c = (¹/₂(1 + 19 + 3 + 7)) - 7
g_c = 8 in
Thus. combined moment about point O is;
M_o = (W_m × g_m) + (W_c × g_c)
M_o = (3.2 × 12.5) + (10.3 × 8)
M_o = 122.4 lb.in
Since positive then it is counterclockwise. Thus;
M_o = 122.4 lb.in (ccw)
The image of this question is missing and so i have attached it.
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A complex Brayton-cycle power plant using intercooling, reheat, and regeneration is analyzed using the cold air standard method. Air is compressed from State 1 to State 2 using a compressor with a pressure ratio of RP1. An intercooler is used to cool the air to State 3 before entering a second compressor with a pressure ratio of RP2. The compressed air exits at State 4 and is preheated in a regenerator that uses the exhaust air from the low pressure turbine. The preheated air enters the combustor at State 5 and is heated to State 6 where it enters the high pressure turbine. The air exits the turbine at State 7 and is heated in a reheat combustor to State 8. The air expands in a low pressure turbine to State 9 where it enters the counterflow regenerator with an effectiveness of RE. Given the specified operating conditions determine the efficiency and other values listed below. The specific heat ratio and gas constant for air are given as k
[tex]
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<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Time Picker</title>
</head>
<body>
<!--24 Hours format-->
<input type="time" placeholder="Enter Time" />
<input type="date">
</body>
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[/tex]
A wood pole with a diameter of 10 in. has a moisture content of 5%. The fiber saturation point (FSP) for this wood is 30%. The wood shrinks or swells 1% (relative to the green dimensions) in the radial direction for every 5% change in moisture content below FSP. a. What would be the percent change in the wood's diameter if the wood's moisture is increased to 55%? b. Would the wood swell or shrink? c. What would be the new diameter?
Answer:
a) Δd(change in wood diameter) = 5%
b) The wood would swell since the moisture content is increasing which will also led to increase in the wood's diameter
C) new diameter (D2) = 10.5 in
Explanation:
Wood pole diameter = 10 inches
moisture content = 5%
FSP = 30%
A) The percentage change in the wood's diameter
note : moisture fluctuations from 5% to 30% causes dimensional changes in the wood but above 30% up to 55% causes no change. hence this formula can be used to calculate percentage change in the wood's diameter
Δd/d = 1/5(30 - 5)
Δd/d = 5%
Δd = 5%
B) would the wood swell or shrink
The wood would swell since the moisture content is increasing which will also led to increase in the wood's diameter
C) The new diameter of the wood
D2 = D + D( [tex]\frac{M1}{100}[/tex] )
D = initial diameter= 10 in , M1 = initial moisture content = 5%
therefore D2 = 10 + 10( 5/100 )
new diameter (D2) = 10.5 in
The change in the diameter of the wood would be 5%
the new diameter would be 10.5 inches
Wood pole diameter = 10 inches
Moisture content = 5%
Fiber saturation point = 30 %
The change in diameter would be[tex]\frac{1}{5} (30-5)[/tex]
= 25/5
= 5%
The percentage change in the diameter of the wood would be 5%
b. This wood is going to rise up instead of shrinking. This is due to the fact that the moisture content that it has has gone up by 55%
c. The new diameter that this wood would have
diameter = 10
moisture = 5%
D = D+D(m)
= 10 + 10(5%)
= 10.5 inches
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A 1/150 scale model is to be usedin a towing tank to study the water motion near the bottom of a shallow channel as a large barge passes over. (See Video V7.16.) Assume that the model is operated in accordance with the Froude number criteria for dynamic similitude. The prototype barge moves at a typical speed of 15 knots. (a) At what speed (in ft/s) should the model be towed
Answer:
The speed will be "3.58 ft/s". The further explanation is given below.
Explanation:
Number of knots
= 15
For the similarity of Froude number:
⇒ [tex]\frac{V_{m}}{\sqrt{g_{m}l_{m}} }=\frac{V}{\sqrt{gl} }[/tex]
Here,
[tex]l = length[/tex]
[tex]g_{m}=g[/tex]
⇒ [tex]\frac{V_{m}}{V}=\sqrt{\frac{l_{m}}{l} }[/tex]
[tex]V_{m}=\sqrt{\frac{1}{50} }\times number \ of \ knots[/tex]
[tex]=\sqrt{\frac{1}{50}}\times 15[/tex]
[tex]=2.12 \ knots[/tex]
Now,
⇒ [tex]1 \ knots=0.514\times 3.281[/tex]
[tex]=1.69 \ ft/s[/tex]
So that,
⇒ [tex]V_{m}=2.12\times 1.69[/tex]
[tex]=3.58 \ ft/s[/tex]
A high molecular weight hydrocarbon gas A is fed continuously into a heated mixed flow reactor (0.1liter) where it is thermally cracked into lower molecular weight materials collectively called R as the reaction stoichiometry A 5R. Find the space velocity if molar feed rate was 300millimol/ hr and the feed concentration was 100millimol / lit.
Answer:
Space velocity = 30 hr⁻¹
Explanation:
Space velocity for reactors express how much reactor volume of feed or reactants can be treated per unit time. For example, a space velocity of 3 hr⁻¹ means the reactor can process 3 times its volume per hour.
It is given mathematically as
Space velocity = (volumetric flow rate of the reactants)/(the reactor volume)
Volumetric flowrate of the reeactants
= (molar flow rate)/(concentration)
Molar flowrate of the reactants = 300 millimol/hr
Concentration of the reactants = 100 millimol/liter
Volumetric flowrate of the reactants = (300/100) = 3 liters/hr
Reactor volume = 0.1 liter
Space velocity = (3/0.1) = 30 /hr = 30 hr⁻¹
Hope this Helps!!!
Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.20 MPa and 258C at a rate of 0.07 kg/s, and it leaves at 1.2 MPa and 708C. The refrigerant is cooled in the condenser to 448C and 1.15 MPa, and it is throttled to 0.21 MPa. Disregarding any heat transfer and pressure drops in the connecting lines between the components, show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the rate of heat removal from the refrigerated space and the power input to the compressor, (b) the isentropic efficiency of the compressor, and (c) the COP of the refrigerator.
(a) A duct for an air conditioning system has a rectangular cross section of 1.8 ft × 8 in. The duct is fabricated from galvanized iron. Determine the Reynolds number for a flow rate of air of 5400 cfm at 100 °F and atmospheric pressure (g=0.0709 lbf/ft3 u=1.8×10-4ft2/s and m=3.96×10-7lbf.s/ft2) (9 points)
Answer:
Reynolds number = 654350.92
Explanation:
Given data:
Cross section of rectangular cross section = 1.8ft * 8 in ( 8 in = 2/3 ft )
Flow rate of air = 5400 cfm = 90 ft^3 / sec
v ( kinematic viscosity of air ) = 1.8*10^-4 ft^2/s
Reynolds number
Re = VDn / v
Dn ( hydraulic diameter ) = 4A / P
where A = area, P = perimeter
a = 1.8 ft ( length )
b = 2/3 ft ( width )
hence Dn = [tex]\frac{4(ab)}{2(a+b)}[/tex] = [tex]\frac{4(1.8*0.6667}{2(1.8+0.6667)}[/tex] = 0.9729 ft
V ( velocity of air flow ) = [tex]\frac{Q}{\pi /4 * Dn^2 }[/tex] = [tex]\frac{90}{\pi /4 * 0.9729^2 }[/tex] = 121.064 ft/sec
back to Reynolds equation
Re = VDn / v -------------- equation 1
V = 121.064 ft/sec
Dn = 0.9729 ft
v = 1.8*10^-4 ft^2/s
insert the given values into equation 1
Re = (121.064 * 0.9729 ) / 1.8*10^-4
= 654350.92
Example 1: the two dimensional points P1(0,0) and P2(1,0) and the two tangents P', (1,1) and P2 (0,-1).find the equation of the curve P(u).
Answer: (0,0)+ (1,0)= 1 lines upwards( suggesting that this is a line graph not saying it is but as an example) an (1,1) and (0,-1) all make a small square ( as this is a 2 dimensional graph that it has a negative side too,(below the positive side)) i hope this helps and is what you are looking for
Explanation:
An electron is traveling with initial kinetic energy K in a uniform electric field. The electron comes to rest momentarily after traveling a distance d.
a. What is the magnitude of the electric field?
b. What is the direction of the electric field?
1. In the direction of the electron's motion.
2. Opposite to the direction of the electron's motion.
3. Perpendicular to the direction of the electron's motion
c. What If? Fluoride ions (which have the same charge as an electron) are initially moving with the same speed as the electrons from part (a) through a different uniform electric field. The ions come to a stop in the same distance d. Let the mass of an ion be M and the mass of an electron be m. Find the ratio of the magnitude of electric field the ions travel through to the magnitude of the electric field found in part (a). (Use the following as necessary: d, K, m, M, and e for the charge of the electron.)
Answer:
a. The magnitude of the electric field is [tex]E = -\dfrac{K}{e \cdot S}[/tex]
b. 1. In the direction of the electron's motion
c. The ratio of the magnitude of the electric field the ions travel through to the magnitude of electric field for the electrons is M:m or 34634.6:1
Explanation:
The change in kinetic energy of electron = [tex]\dfrac{1}{2} \cdot m \cdot v^2_f - \dfrac{1}{2} \cdot m \cdot v^2_i[/tex]
Given that the work done, W = the change in kinetic energy of electron, we have;
[tex]W = \dfrac{1}{2} \cdot m \cdot v^2_f - \dfrac{1}{2} \cdot m \cdot v^2_i[/tex]
Given that the final velocity is 0, we have;
[tex]W =- \dfrac{1}{2} \cdot m \cdot v^2_i = -K[/tex]
However, we have;
W = E·q·S
Where:
q = Particle charge = Electron charge = e
S = Particle displacement
E = Electric field strength
Therefore;
W = -K = E·q·S
Which gives;
[tex]E = -\dfrac{K}{e \cdot S}[/tex]
b. The direction of the electric field is the direction of the force exerted by the electric field on a positive charge
Given that the particle is an electron, its direction is opposite to that of a positive charge, however whereby the electron is brought to rest the direction of the field is in the same direction of as that of the electron's motion
The correct option is therefore, 1. In the direction of the electron's motion
c. Given that the mass of fluoride ion, Fe⁻, M = 3.155×10⁻²⁶ kg
The mass of an electron, m = 9.1094×10⁻³¹ kg
We have;
x × 0.5 × m × v² = 0.5×M×v²
∴ x = M/m
Therefore. the kinetic energy of the fluoride ion is M/m multiplied by the kinetic energy of the electron
x × 0.5 × 9.1094×10⁻³¹ × v² = 0.5×3.155×10⁻²⁶×v²
Therefore, x = (3.155×10⁻²⁶)÷(9.1094×10⁻³¹) = 34634.6
Therefore, the kinetic energy of the Fluoride ion is 34634.6 times that of the kinetic energy of the electron
Whereby the electric field strength is directly proportional to the kinetic energy, we have;
[tex]E_{(electron)} = -\dfrac{K_{(electron)}}{e \cdot S}[/tex]
[tex]E_{(fluoride \ ion)} = -\dfrac{K_{(fluoride \ ion)}}{e \cdot S}[/tex]
Which gives;
[tex]\dfrac{E_{(fluoride \ ion)} }{E_{(electron)}} = \dfrac{-\dfrac{K_{(fluoride \ ion)}}{e \cdot S}}{ -\dfrac{K_{(electron)}}{e \cdot S}} = \dfrac{{K_{(fluoride \ ion)}}}{ {K_{(electron)}}}[/tex]
[tex]\dfrac{E_{(fluoride \ ion)} }{E_{(electron)}} = \dfrac{\dfrac{M}{m} \times {K_{(electron)}}}{ {K_{(electron)}}} = \dfrac{M}{m}[/tex]
[tex]\dfrac{E_{(fluoride \ ion)} }{E_{(electron)}} = \dfrac{34634.6 \times {K_{(electron)}}}{ {K_{(electron)}}} = 34634.6[/tex]
The magnitude of the uniform electric field in the fluoride ion path is 34634.6 times that of the magnitude of the electric field in the electron path.
The ratio of the magnitude of the electric field the ions travel through to the magnitude of electric field for the electrons is M:m or 34634.6:1
Consider a 2-shell-passes and 8-tube-passes shell-and-tube heat exchanger. What is the primary reason for using many tube passes
Answer:
See explanation
Explanation:
Solution:-
- The shell and tube heat exchanger are designated by the order of tube and shell passes.
- A single tube pass: The fluid enters from inlet, exchange of heat, the fluid exits.
- A multiple tube pass: The fluid enters from inlet, exchange of heat, U bend of the fluid, exchange of heat, .... ( nth order of pass ), and then exits.
- By increasing the number of passes we have increased the "retention time" of a specific volume of tube fluid; hence, providing sufficient time for the fluid to exchange heat with the shell fluid.
- By making more U-turns we are allowing greater length for the fluid flow to develop with " constriction and turns " into turbulence. This turbulence usually at the final passes allows mixing of fluid and increases the heat transfer coefficient by:
U ∝ v^( 0.8 ) .... ( turbulence )
- The higher the velocity of the fluids the greater the heat transfer coefficient. The increase in the heat transfer coefficient will allow less heat energy carried by either of the fluids to be wasted ; hence, reduced losses.
Thereby, increases the thermal efficiency of the heat exchanger ( higher NTU units ).
What is the final temperature after compression of a diesel cycle if the initial temperature is 32C and clearance is 8%
Answer:
863 K
Explanation:
See the attachment
Air enters the compressor of a regenerative gas-turbine engine at 300 K and 100 kPa, where it is compressed to 800 kPa and 580 K. The regenerator has an effectiveness of 72%, and the air enters the turbine at 1200 K. For a turbine efficiency of 86%, draw the cycle on T-s diagram and find: a) Heat transfer in the regenerator. b) Thermal efficiency. (114.2kJ/kg,, 36%)
Answer:
a) The amount of heat transfer in the regenerator, q = 114.12 kJ/kg
b) Thermal efficiency = 35.9%
Explanation:
The calculations are neatly handwritten and attached as files to this solution for easiness of expression and clarity. The cycle is also drawn on the T - S diagram and included in the attached files. Check the files below for the complete calculation.
I hope this helps!
An air-standard Diesel cycle has a compression ratio of 16 and a cutoff ratio of 2. At the beginning of the compression process, air is at 95 kPa and 27 degree Celsius.
(a) Determine the temperature after the heat-addition process.
(b) Determine the thermal efficiency.
(c) Determine the mean effective pressure. Solve the problem in the constant heat supposition.
Answer:
a) T₃ = 1818.8 K
b) η = 0.614 = 61.4%
c) MEP = 660.4 kPa
Explanation:
a) According to Table A-2 of The ideal gas specific heat of gases, the properties of air are as following:
At 300K
The specific heat capacity at constant pressure = [tex]c_{p}[/tex] = 1.005 kJ/kg.K,
The specific heat capacity at constant volume = [tex]c_{v}[/tex] = 0.718 kJ/kg.K
Gas constant R for air = 0.2870 kJ/kg·K
Ratio of specific heat k = 1.4
Isentropic Compression :
[tex]T_{2}[/tex] = [tex]T_{1}[/tex] [tex](v1/v2)^{k-1}[/tex]
= 300K ([tex]16^{0.4}[/tex])
[tex]T_{2}[/tex] = 909.4K
P = Constant heat Addition:
[tex]P_{3}v_{3} / T_{3} = P_{2} v_{2} /T_{2}[/tex]
[tex]T_{3}=v_{3}/v_{2}T_{2}[/tex]
2[tex]T_{2}[/tex] = 2(909.4K)
= 1818.8 K
b) [tex]q_{in}[/tex] = [tex]h_{3}-h_{2}[/tex]
= [tex]c_{p}[/tex] ([tex]T_{3}[/tex] - [tex]T_{2}[/tex])
= (1.005 kJ/kg.K)(1818.8 - 909.4)K
= 913.9 kJ/kg
Isentropic Expansion:
[tex]T_{4}[/tex] = [tex]T_{3}[/tex] [tex](v3/v4)^{k-1}[/tex]
= [tex]T_{3}[/tex] [tex](2v_{2} /v_{4} )^{k-1}[/tex]
= 1818.8 K (2 / 16[tex])^{0.4}[/tex]
= 791.7K
v = Constant heat rejection
[tex]q_{out}[/tex] = μ₄ - μ₁
= [tex]c_{v} ( T_{4} - T_{1} )[/tex]
= 0.718 kJ/kg.K (791.7 - 300)K
= 353 kJ/kg
η[tex]_{th}[/tex] = 1 - [tex]q_{out}[/tex] / [tex]q_{in}[/tex]
= 1 - 353 kJ/kg / 913.9 kJ/kg
= 1 - 0.38625670
= 0.6137
= 0.614
= 61.4%
c) [tex]w_{net}._{out}[/tex] = [tex]q_{in}[/tex] - [tex]q_{out}[/tex]
= 913.9 kJ/kg - 353 kJ/kg
= 560.9 kJ/kg
[tex]v_{1} = RT_{1} /P_{1}[/tex]
= (0.287 kPa.m³/kg/K)*(300 K) / 95 kPa
= 86.1 / 95
= 0.9063 m³/kg = v[tex]_{max}[/tex]
[tex]v_{min} =v_{2} = v_{max} /r[/tex]
Mean Effective Pressure = MEP = [tex]w_{net,out}/v_{1} -v_{2}[/tex]
= [tex]w_{net,out}/v_{1}(1-1)/r[/tex]
= 560.9 kJ/kg / (0.9063 m³/kg)*(1-1)/16
= (560.9 kJ / 0.8493m³) (kPa.m³/kJ)
= 660.426 kPa
Mean Effective Pressure = MEP = 660.4 kPa
The temperature after the addition process is 1724.8k, the thermal efficiency of the engine is 56.3% and the mean effective pressure is 65.87kPa
Assumptions made:
The air standard assumptions are madeThe kinetic and potential energy changes are negligibleThe air in the system is an ideal gas with variable or different specific heat capacity.a) The temperature after the addition process:
Considering the process 1-2, Isentropic expansion
at
[tex]T_1=300k\\u_1=214.07kJ/kg\\v_o_1=621.3\\v_o_2=\frac{v_2}{v_1} *v_o_1[C.R=16]=v_2/v_1\\v_o_2=(v_2/v_1)v_o_1=1/16*621.2=38.825[/tex]
From using this value, v[tex]_o_2[/tex]=38.825, solve for state point 2;
[tex]T_2=862.4k\\h_2=890.9kJ/kg[/tex]
Considering the process 2-3 (state of constant heat addition)
[tex]\frac{p_3v_3}{t_3}=\frac{p_2v_2}{t_2} \\\\T_3=\frac{P_3V_3T_2}{V_2} \\T_3=(\frac{V_3}{V_2}) T_2\\\frac{v_3}{v_2}=2\\T_3=2(862.4)=1724.8k\\[/tex]
NB: p[tex]_3[/tex]≈p[tex]_2[/tex]
b) The thermal efficiency of the engine is
Q[tex]_i_n[/tex]=h[tex]_3-h_2[/tex] = 1910.6-890.9=1019.7kJ/kg
Considering process 3-4,
[tex]v_o_4=\frac{v_A}{v_2}\\ v_o_3 =\frac{V_a}{V_2}*\frac{v_2}{v_3}\\v_o_3=\frac{16}{2}*4.546\\v_o_3=36.37;v_4=659.7kJ/kg[/tex]
Q[tex]_o_u_t=v_4-u_1=659.7-214.07=445.3kJ/kg[/tex]
nth = [tex]1-\frac{Q_o_u_t}{Q_i_n}=1-\frac{445.63}{1019.7}=0.5629*100=56.3%[/tex]%
The thermal efficiency is 56.3%
W[tex]_n_e_t[/tex]=[tex]Q_i_n-Q_o_u_t=574.07kJ/kg[/tex]
[tex]v_1=\frac{RT_1}{p_1}=\frac{0.287*300}{95}=0.906m^3/kg\\v_2=v_1/16=0.05662m^3/kg\\[/tex]
Therefore, the mean effective pressure of the system engine is
[tex]\frac{W_n_e_t}{v_1-v_2}=675.87kPa[/tex]
The mean effective pressure is 65.87kPa as calculated above
Learn more about mean effective pressure
https://brainly.com/question/19309495
(a) Design a high-pass filter with a cutoff frequency of 40 kHz. Use0.01 uF capacitor and an appropriate resistor. B) Sketch and label the circuit. C) What is the gain of the filter at the cutoff frequency? Give your answer both as ratio (Vout/Vin) and in dB. D) What is the gain of the filter at a frequency of 55 kHz? Give your answer both as a ratio (Vout/Vin) and in dB.
Answer:
a) 397.89 ohm
b) attached below
c) 0.707 as a ratio
Gain in dB = 20 log 0.707 = -3 dB
d) 0.8087
Gain in dB = 20 log [tex]|\frac{Vout}{Vin}|[/tex] = -1.844 dB
Explanation:
A) Find the appropriate resistor
c = 0.01 uf
fc = 40 kHz
cut-off frequency ; fo = [tex]\frac{1}{2\pi RC }[/tex]
from the above equation R = [tex]\frac{1}{2\pi foC}[/tex] = 397.89 ohm
B) sketch of the circuit is attached
C) The gain of the filter at the cutoff frequency
fc = 40 kHz,
C = 0.01 uF ⇒ [tex]\frac{-j}{2\pi foC }[/tex] = -j 397.89
Vout = Vin * ( R / R- C )
Vout = Vin * ( 397.89 / (397.89 - j 397.89))
Vout = [tex]\frac{1}{\sqrt{2} }[/tex] Vin ∠45⁰
therefore gain = |[tex]\frac{Vout}{Vin }[/tex]| = [tex]\frac{1}{\sqrt{2} }[/tex] = 0.707 as a ratio
Gain in dB = 20 log 0.707 = -3 dB
D) Gain of filter at 55 kHz
c = 0.01 uF = [tex]\frac{-J}{2\pi foC }[/tex] = -j 289.373 ohms
Vout = Vin * [tex]\frac{R}{R-C}[/tex]
= Vin * ( 397.89 / ( 397.89 - j 289.373))
Gain in ratio [tex]|\frac{Vout}{Vin}|[/tex] = 0.8087 ∠ 36.03⁰
therefore gain in ratio = 0.8087
Gain in dB = 20 log [tex]|\frac{Vout}{Vin}|[/tex] = -1.844 dB
A cylindrical specimen of some metal alloy having an elastic modulus of 106 GPa and an original cross-sectional diameter of 3.9 mm will experience only elastic deformation when a tensile load of 1660 N is applied. Calculate the maximum length of the specimen before deformation if the maximum allowable elongation is 0.41 mm.
Answer:
L= 312.75 mm
Explanation:
given data
elastic modulus E = 106 GPa
cross-sectional diameter d = 3.9 mm
tensile load F = 1660 N
maximum allowable elongation ΔL = 0.41 mm
to find out
maximum length of the specimen before deformation
solution
we will apply here allowable elongation equation that is express as
ΔL = [tex]\dfrac{FL}{AE}[/tex] ....................1
put here value and we get L
L = [tex]\dfrac{0.41\times 10^{-3}\times \dfrac{\pi}{4}\times (3.9\times 10^{-3})^2\times 106\times 10^9}{1660}[/tex]
solve it we get
L = 0.312752 m
L= 312.75 mm