Answer:
The average reactive power is [tex]I_{rms}V_{rms} cos \phi[/tex]
Explanation:
For a single-phase AC circuit;
the peak current in the circuit is given as [tex]I_o[/tex]
the root-mean-square current is given by;
[tex]I_{rms} = \frac{I_o}{\sqrt{2}}[/tex]
the peak voltage in the circuit is given as [tex]V_o[/tex]
the root-mean-square voltage is given by;
[tex]V_{rms} = \frac{V_o}{\sqrt{2} }[/tex]
The average reactive power is given by
[tex]P_{avg} = I_{rms}V_{rms} cos \phi[/tex]
where;
[tex]cos \phi \ is \ the \ power \ factor[/tex]
Therefore, the average reactive power is [tex]I_{rms}V_{rms} cos \phi[/tex]
It is known that the kinetics of recrystallization for some alloy obey the Avrami equation, and that the value of n in the exponential is 2.4. If, at some temperature, the fraction recrystallized is 0.30 after 100 min, determine the rate of recrystallization at this temperature.
Answer:
rate = 7.580 × [tex]10^{-3}[/tex] /min
Explanation:
given data
value of n = 2.4
fraction recrystallized = 0.30
time = 100 min
solution
we will get here rate of recrystallization at this temperaturewe use here avrami equation that is
y = 1 - exp (-k [tex]t^n[/tex] ) ................1
we get hete first k
k = [tex]-\frac{ln (1-y)}{t^n}[/tex]
put heer value n is 2.4 and y = 0.30 and t is 100
k = [tex]-\frac{ln (1-0.30)}{100^{2.4}}[/tex]
k = 5.65 × [tex]10^{-6}[/tex]
now we get here [tex]t^{0.5}[/tex]
value of t at y 0.5
[tex]t^{0.5}[/tex] = [tex][\frac{-ln(1-y)}{k}]^{1/n}[/tex]
[tex]t^{0.5}[/tex] = [tex][\frac{-ln(1-0.5)}{5.65\times 106{-6}}]^{1/2.4}[/tex]
[tex]t^{0.5}[/tex] = 131.923 min
and
rate = 1 ÷ [tex]t^{0.5}[/tex]
rate = 1 ÷ 131.923
rate = 7.580 × [tex]10^{-3}[/tex] /min
In a two dimensional flow, the component of the velocity along the X-axis and the Y-axis are u = ax2 + by + cy2 and v = cxy. What should be the condition for the flow field to be incompressible
Answer:
The condition for the flow field to be incompressible is independent of a and c
Explanation:
We are given the component of the velocity along the X-axis and the Y-axis as;
u = ax² + by + cy²
v = cxy
Now, the condition for the flow to be incompressible is;
du/dx + dv/dy = 0
Now,
du/dx = 2ax
dv/dy = cx
Thus;
2ax + cx = 0
(2a + c)x = 0
Thus,the condition for the flow field to be incompressible is independent of a and c
CRM software programs enable sales people to track of their customer contact information, needs, sales status, and other useful information. True False
Answer:
The correct answer is True
Explanation:
Most business organizations especially those that are into sales, call centers, even individuals that are into marketing use CRM (Customer Relationship Management) software to drive their business forward by enabling them to interact more with customers and strive to provide better customer service. This is achievable because The software (CRM) which is a business tool stores customers' information ranging from names, contact info, sales, and other important information based on the need of the salespeople (organization) to track, meet and respond to customers needs. CRM benefits range from getting to know more about prospective or existing customers to building a better relationship with customers so as to retain them and allow better communication between customers in a bid to meet their demands.
g What is the difference between surface erosion and bulk degradation, and for what application is each best suited
Explanation:
The main difference between surface erosion and bulk degradation is that in surface erosion as the name implies that the material or polymer begins to erode or degrade only from the external surface until it reaches the interior of the material. However, in bulk degradation, the material undergoes complete degradation from within and outside the material.
Surface erosion is best applied in pharmaceuticals in terms of drug delivery into the body, while bulk degradation is best applied in plastics which may degrade in any form.
In a non air-entrained concrete mixture you should assume this % of air by volume for the purposes of concrete mixture proportioning: _______ %
Answer:200%
Explanation:
so it can melt to use it later?
Calculate the drain current in an NMOS transistor if Kn = 400 μA/V2, VT N = 0.5 V, λ = 0.02 V−1, VGS = 5 V, and VDS = 6 V. (Round off the answer to two decimal places.)
Answer:
Drain current = 4050 μA
Explanation:
Determine the drain current in an NMOS transistor
Given data :
Kn = 400 μA/V^2
Vt = 0.5 v
λ = 0.02 V^−1
Vgs = 5 V
Vds = 6 v
Id = ?
The drain current can be calculated using the formula below
[tex]I_{D} = \frac{1}{2} U_{n} C_{OX} \frac{W}{L} ( V_{GS} - V_{t} ) ^2[/tex]
= [tex]\frac{1}{2} Kn ( Vgs - Vt)^2[/tex]
= 1/2 ( 400 μA/V^2) ( 5 - 0.5 )^2
= (200 μA/V^2) * (20.25 v^2)
= 4050 μA
Service entrance conductors must be kept a minimum of ____ feet from the sides and bottom of windows that can be opened
A heat exchanger is to heat water (cp = 4.18 kJ/kg·°C) from 25°C to 60°C at a rate of 0.5 kg/s. The heating is to be accomplished by geothermal water (cp = 4.31 kJ/kg·°C) available at 140°C at a mass flow rate of 0.3 kg/s. Determine the rate of heat transfer in the heat exchanger and the exit tempera
Answer:
73.15 kW, 196.6°C
Explanation:
Energy in - Energy out = change in energy
[tex]E_{in}-E_{out}=\Delta E\\\\\Delta E=0\\\\E_{in}-E_{out}=0\\\\E_{in}=E_{out}\\\\Q_{in}+\dot mh_1=\dot mh_2\\\\Q_{in}=\dot mh_2-\dot mh_1\\\\Q_{in}=\dot m c_p(T_2-T_1)[/tex]
The rate of heat transfer to cold water is given as:
[tex]Q_{in}=\dot m c_p(T_2-T_1)\\\\\dot m =0.5\ kg/s,c_p=4.18\ kJ/kg.^oC, T_2=60^oC,T_1=25^oC\\\\Q_{in}=(0.5 *4.18)(60-25)=73.15\ kW[/tex]
For the geothermal water:
[tex]Q_{in}=\dot m c_p(T_2-T_1)\\\\\dot m =0.3\ kg/s,c_p=4.31\ kJ/kg.^oC, ,T_1=140^oC\\\\T_2=\frac{Q}{\dot m c_p} +T_1=\frac{73.15}{0.3*4.31}+140=196.6\\ \\T_2=196.6^oC[/tex]
A high strength waste having an ultimate CBOD of 1,000 mg/L is discharged to a river at a rate of 2 m3 /s. The river has an ultimate CBOD of 10 mg/L and is flowing at a rate of 8 m3 /s. Assuming a reaction rate coefficient of 0.1/day, calculate the ultimate and 5-day CBOD of the waste at the point of discharge (0 km) and 20 km downstream. The river is flowing at a velocity of 10 km/day.
Answer:
Attached below is the detailed solution
answer:
The Ultimate CBOD of waste water at (0) km and 20 Km
= 81.84 mg/l , 67 mg/l
Explanation:
Given Data :
UBOD of waste stream = 1000 mg/l
Volumetric flow rate of waste water = 2 m^3 / s
UBOD of River = 10 mg/l
Volumetric flow rate of river = 8 m^3 / s
reaction rate coefficient = 0.1/day
Velocity of river = 10km/day
The Ultimate CBOD of waste water at (0) km and 20 Km
= 81.84 mg/l , 67 mg/l
At 7:00PM the temperature was 40 degrees F. If the temperature dropped steadily at a rate of 6 degrees per hour, what was the temperature at 11:00 PM? Do you know what it is
Answer:
Temperature at 11:00 PM = 16 degree
Explanation:
Given:
Temperature at 7:00 PM = 40 degree
Decrease rate = 6 degree per hour
Find:
Temperature at 11:00 PM
Computation:
Total time = 11 - 7 = 4 hour
Total decrease in temperature = 4 x 6 = 24 degree
Temperature at 11:00 PM = 40 - 24
Temperature at 11:00 PM = 16 degree
A single crystal of copper yields under a shear stress of 0.62 MPa. The shear modulus of copper is 7.9106 psi. Calculate the approximate ratio of the theoretical to the experimental shear strengths.
Answer:
6370
Explanation:
Given data:
shear stress = 0.62 MPa
shear modulus of copper = 7.9 GPa
Determine the approximate ratio of the theoretical to the experimental shear strengths
lets assume the theoretical yield shear stress = 1/2 shear modulus
theoretical yield shear stress = 7.9 / 2 = 3.95 GPa ≈ 3950 MPa
required ratio = [tex]\frac{3950}{0.62}[/tex] ≈ 6370
Which type of engineer finds his or her skills needed in the electronics, architectural, medical, and aerospace industries?
nuclear engineer
chemical engineer
biomedical engineer
mechanical engineer
Answer:
mechanical engineer
Explanation:
Determine the minimum radius of a horizontal curve required for a highway if the design speed is 70 mph and the superelevation rate is 0.08.
Answer:
1819.4 ft
Explanation:
Let us assume the coefficient of side friction is 0.10
The radius of curve is given by the formula:
[tex]R=\frac{V^2}{g(f_s+\frac{e}{100} )}[/tex]
Where R is the minimum radius of a horizontal curve, V is the speed, f is coefficient of side friction and e/100 = super elevation rate, g =acceleration due to gravity
Given that:
V = 70 mph = (70 * 1.467) ft/s = 102.69 ft/s, g =32.2 ft/s², e/100 = 0.08, f= 0.1
[tex]R=\frac{V^2}{g(f_s+\frac{e}{100} )}=\frac{102.69^2}{32.2(0.1+0.08)}=1819.4\ ft[/tex]
the minimum radius of a horizontal curve is 1819.4 ft
Para un intercambiador de calor encargado de precalentar pulpa de fruta, se utiliza agua caliente que entra a 180°C y sale a 78°C, mientras que la pulpa de fruta entra a 3°C y sube su temperatura hasta 55°C. Realizar los esquemas de perfil de temperaturas para un intercambiador de calor que funcione en paralelo y en contracorriente. Además, calcular LMTD.
Answer:
La diferencia media logarítimica de temperatura del intercambiador en paralelo es aproximadamente 75.466 ºC.
La diferencia media logarítmica de temperatura del intercambiador en contracorriente es aproximadamente 97.881 ºC.
Explanation:
De la teoría de Transferencia de Calor tenemos que un intercambiador de calor en paralelo presenta las siguientes dos características:
1) Tanto el fluido caliente como el fluido frío entran por el mismo lado.
2) Tanto el fluido caliente como el fluido frío salen por el mismo lado.
Mientras que el intercambiador de calor en contracorriente tiene que:
1) El fluido caliente y el fluido frío entran por lados opuestos.
2) El fluido caliente y el fluido frío salen por lados opuestos.
A continuación, anexamos los esquemas de perfil de cada intercambiador.
Ahora, la Diferencia Media Logarítimica de Temperatura ([tex]\Delta T_{lm}[/tex]), medida en grados Celsius, queda definida como sigue:
[tex]\Delta T_{lm} = \frac{\Delta T_{1}-\Delta T_{2}}{\ln \frac{\Delta T_{1}}{\Delta T_{2}} }[/tex] (Eq. 1)
Donde [tex]\Delta T_{1}[/tex] y [tex]\Delta T_{2}[/tex] son las diferencias de temperatura de los fluidos en cada extremo del intercambiador, medido en grados Celsius.
Procedemos a determinar esas diferencias y la Diferencia Media Logarítimica de Temperatura para cada configuración:
Intercambiador en paralelo
[tex]\Delta T_{1} = 180\,^{\circ}C-3\,^{\circ}C[/tex]
[tex]\Delta T_{1} = 177\,^{\circ}C[/tex]
[tex]\Delta T_{2} = 78\,^{\circ}C - 55\,^{\circ}C[/tex]
[tex]\Delta T_{2} = 23\,^{\circ}C[/tex]
[tex]\Delta T_{lm} = \frac{177\,^{\circ}C-23\,^{\circ}C}{\ln \frac{177\,^{\circ}C}{23\,^{\circ}C} }[/tex]
[tex]\Delta T_{lm} \approx 75.466\,^{\circ}C[/tex]
La diferencia media logarítimica de temperatura del intercambiador en paralelo es aproximadamente 75.466 ºC.
Intercambiador en contracorriente
[tex]\Delta T_{1} = 180\,^{\circ}C-55\,^{\circ}C[/tex]
[tex]\Delta T_{1} = 125\,^{\circ}C[/tex]
[tex]\Delta T_{2} = 78\,^{\circ}C-3\,^{\circ}C[/tex]
[tex]\Delta T_{2} = 75\,^{\circ}C[/tex]
[tex]\Delta T_{lm} = \frac{125\,^{\circ}C-75\,^{\circ}C}{\ln \frac{125\,^{\circ}C}{75\,^{\circ}C} }[/tex]
[tex]\Delta T_{lm} \approx 97.881\,^{\circ}C[/tex]
La diferencia media logarítmica de temperatura del intercambiador en contracorriente es aproximadamente 97.881 ºC.
A signal processor has a reliability of 0.90. Because of the low reliability a redundant signal processor is to be added. However, a signal splitter must be added before the signal processors, and a comparator must be added after the signal processors. Each of these new components has a reliability of 0.95. Does adding a redundant signal processor increase the system reliability
Answer:
0.9732
Explanation:
A signal splitter must be placed before a processor and a comparator be placed after a processor.
This contains a series combination of a splitter, processor and comparator. Let R1 represent the reliability of the first subsystem and R2 be the reliability of the added redundant system.
Given: R(processor) = 0.9, R(new components) = 0.95 (i.e. splitter, new processor, comparator)
R1 = series combination of splitter, processor and comparator
R1 = R(splitter) × R(processor) × R(comparator) = 0.95 × 0.9 × 0.95 = 0.81225
R2 = series combination of splitter, processor and comparator
R2 = R(splitter) × R(new processor) × R(comparator) = 0.95 × 0.95 × 0.95 = 0.8574
R2 is the redundant system which is connected in parallel with R1, hence:
R(system) = 1 - (1 - R1)(1 - R2) = 1 - (1 - 0.81225)(1 - 0.8574)
R(system) = 0.9732
Some measurements on a blood sample at 37 ˚C (98.6 ˚F) indicate a shearing stress of 0.540 N/m2 for a corresponding rate of shearing strain of 198 s-1. Determine (a) the apparent viscosity of the blood and (b) its ratio to the viscosity of water at the same temperature.
Answer:
[tex]0.00273\ \text{Pa s}[/tex]
3.944
Explanation:
[tex]\tau[/tex] = Shearing stress = [tex]0.54\ \text{N/m}^2[/tex]
[tex]\dot{\gamma}[/tex] = Rate of shearing strain = [tex]198\ \text{s}^{-1}[/tex]
(a) Viscosity is given by
[tex]\mu_b=\dfrac{\tau}{\dot{\gamma}}\\\Rightarrow \mu_b=\dfrac{0.54}{198}\\\Rightarrow \mu_b=0.00273\ \text{Pa s}[/tex]
The apparent viscosity of the blood is [tex]0.00273\ \text{Pa s}[/tex]
(b) Viscosity of water at 37 ˚C = 0.0006922 Pa s = [tex]\mu_w[/tex]
The ratio is
[tex]\dfrac{\mu_b}{\mu_w}=\dfrac{0.00273}{0.0006922}\\\Rightarrow \dfrac{\mu_b}{\mu_w}=3.944[/tex]
The required ratio is 3.944
What type of engineer constructs the infrastructure necessary for roads airfields and water ports
Answer:
Civil Engineer
Explanation:
Structural engineers and Civil engineers are the ones who design, build, and maintain the foundation for our modern society.
Like our roads and bridges, drinking water and energy systems, sea ports and airports, and the infrastructure for a cleaner environment and many more.
Contains tires, wheels, engine, transmission, and drive axle assembly.
If you needed to calculate the mass flow rate rather than volumetric flow rate through the Venturi meter how would you go about it
Answer:
Follows are the solution to this question:
Explanation:
Its difference in power supply will be smaller whenever the pressure transducer is being performed. Its transducer sensitivity(s) is often used to calculate its number of changes occurring at voltage output of ([tex]v_o[/tex]) when the supply tension ([tex]v_s[/tex]) changes with the measured pressure ([tex]p_m[/tex]) and the rated tension of transducers ([tex]p_s[/tex]).
[tex]v_o= (s) V_s (\frac{P_m}{P_s})[/tex]
Assume that the density of fresh water is 998 kg/m3 , and the density of salt water is 1025 kg/m3 . The gate weighs 0.448 kN/m (into the page). The gate is 5 m wide, into the page. Determine the height of the fresh water at which the gate opens. (15 points)
Answer:
hello your question lacks the required diagram attached below is the diagram showing the resultant forces at the gate
answer: 1.975 m
Explanation:
Given data :
density of fresh water = 998 kg/m^3
density of salt water = 1025 kg/m^3
gate weight = 0.448 kN/m ≈ 100 Ib/m
attached below is the detailed solution required
A rectangular channel with a width of 2 m is carrying 15 m3/s. What are the critical depth and the flow velocity
Answer:
The critical depth of the rectangular channel is approximately 1.790 meters.
The flow velocity in the rectangular channel is 4.190 meters per second.
Explanation:
From Open Channel Theory we know that critical depth of the rectangular channel ([tex]y_{c}[/tex]), measured in meters, is calculated by using this equation:
[tex]y_{c} = \sqrt[3]{\frac{\dot V^{2}}{g\cdot b^{2}} }[/tex] (Eq. 1)
Where:
[tex]\dot V[/tex] - Volume flow rate, measured in cubic meters per second.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]b[/tex] - Channel width, measured in meters.
If we know that [tex]\dot V = 15\,\frac{m^{3}}{s}[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]b = 2\,m[/tex], then the critical depth is:
[tex]y_{c} = \sqrt[3]{\frac{\left(15\,\frac{m^{3}}{s} \right)^{2}}{\left(9.807\,\frac{m}{s^{2}} \right)\cdot (2\,m)^{2}} }[/tex]
[tex]y_{c} \approx 1.790\,m[/tex]
The critical depth of the rectangular channel is approximately 1.790 meters.
Lastly, the flow velocity ([tex]v[/tex]), measured in meters, is obtained from this formula:
[tex]v = \frac{\dot V}{b\cdot y_{c}}[/tex] (Eq. 2)
If we know that [tex]\dot V = 15\,\frac{m^{3}}{s}[/tex], [tex]b = 2\,m[/tex] and [tex]y_{c} = 1.790\,m[/tex], then the flow velocity in the rectangular channel is:
[tex]v = \frac{15\,\frac{m^{2}}{s} }{(2\,m)\cdot (1.790\,m)}[/tex]
[tex]v = 4.190\,\frac{m}{s}[/tex]
The flow velocity in the rectangular channel is 4.190 meters per second.
A specimen of some metal having a rectangular cross section 9.18 mm x 13.2 mm is pulled in tension with a force of 3310 N, which produces only elastic deformation. Given that the elastic modulus of this metal is 79 GPa, calculate the resulting strain.
Answer: 0.0000084
Explanation:
Given data:
Cross sectional area = 9.18mm*13.22mm
Force N = 3310
Elastic modulus = 79 GPa
Solution:
Area = 9.18mm * 13.22mm
= 121.36mm^2
= π(d)^2
= π(0.121)^2
= 0.05m^2
Stress = F/A
= 3310N/0.05m^2
= 66200Nm^2
Strain = Stress/ modulus of elastic
= 66200/7.9*10^10
= 0.0000084
6-137 Consider a Carnot heat-engine cycle executed in a steady-flow system using steam as the working fluid. The cycle has a thermal efficiency of 30%, and steam changes from saturated liquid to saturated vapor at 275oC during the heat addition process. If the mass flow rate of the steam is 3 kg/s, determine the net power output of this engine, in kW.
Answer:
1417.05 kw
Explanation:
From the question,
The Mass flow rate = 3kg
The Saturated temperature = 275⁰c
The Thermal efficiency = 30%
The enthalpy of vaporization is 1574.5kj/kg
Rate of heat transfer = 3x1574.5 = 4723.5 kW
Thermal efficiency of engine =
0.30 x 4723.5
= 1417.05 kW
This answer is the net power output of this engine, in kW.
Thank you!
In a hydroelectric power plant, water enters the turbine nozzles at 880 kPa absolute with a low velocity. If the nozzle outlets are exposed to atmospheric pressure of 100 kPa, determine the maximum velocity to which water can be accelerated by the nozzles before striking the turbine blades. The maximum velocity is m/s.
Answer:
39.5 m/s
Explanation:
To solve this question, we would use Bernoulli's equation
P₁/ρ + V₁²/2 + gz₁ = P₂/ρ + V₂²/2 + gz₂,
where V₁ = 0 and z₁ = z₂, so that we have
P₁/ρ = P₂/ρ + V₂²/2
making V₂² subject of formula, we have that
V₂² = 2[P₁/ρ - P₂/ρ]
Then we finally go ahead and substitute the values such that
V₂² = 2 [(880000/1000) - (100000/1000)]
V₂² = 2 (880 - 100)
V₂² = 2(780)
V₂² = 1560
V₂ = √1560
V₂ = 39.5 m/s
6-44Determine the COP of a refrigerator that removes heat from the food compartment at a rate of 5040 kJ/h for each kW of power it consumes. Also, determine the rate of heat rejection to the outside air.
Answer:
The correct answer will be "8640 kWh".
Explanation:
The given values are:
Rate (Ql)
= 5040 kJ/h
As we know,
⇒ [tex]COP = \frac{Cooling}{heat \ required}[/tex]
On putting the values, we get
⇒ [tex]=\frac{5040 \ kJ/h}{1 \ kW}[/tex]
⇒ [tex]=1.4[/tex]
Now,
⇒ [tex]Q = Ql + W[/tex]
[tex]= 1 + 1.4[/tex]
[tex]=2.4 \ kW[/tex]
[tex]=2.4\times 3600[/tex]
[tex]=8640 \ kWh[/tex]
What is 22 centimeters in inches
Answer:
8.66142
Explanation:
Answer:
8.66
Explanation:
hope it helps
19. Which symbol in the figure is used to represent a carbon block lightning arrestor?
A. D
ОВ. А
C. B
O D.C
Answer:
C
Explanation:
I drive safe
Determine a safe speed to travel base on
2. A freeway is being designed for a location in rolling terrain. The expected free-flow speed is 55 mph. During the peak hour, it is expected there will be a directional peak-hour volume of 2700 vehicles and 18% heavy vehicles. The PHF is expected to be 0.88. If a LOS no worse than D is desired, determine the necessary number of lanes.
Answer:
Number of necessary lanes = 3
Explanation:
Expected free flow speed = 55 mph
Volume of vehicles expected during peak-hour = 2700
PHF = 0.88
18% = 0.18 for heavy vehicles ( Pt )
Et ( for a rolling terrain ) = 3
Detailed solution attached below
First we calculate the Heavy-vehicle adjustment factor before determining the number of lanes
What is another example of radiation? Warm air risingrisingHeat Heat from an old-fashioned radiatorradiatorBatteriesTouching Touching a stove and burning bur-
ning your hand hand
Answer: what’s the answer
Explanation:
JdjdjdjdjdjdjdjieeowojwjkgkfkjGCZxhlkVzljhdKLHagdfpojglKVldjnCBa
kehrgpiyfealuydvasljfnVjlehgrPIYgefioyGlihv
Answer:
Batteries
Explanation:
They include a lot of radiation in them