Answer:
The correct answer will be "18 degrees AOB".
Explanation:
The given value is:
KTAS = 120
For determining bank angles through standard rate switches, as we understand
⇒ [tex]10 \ percent \ of KTAS +\frac{1}{2} \ of \ the \ number[/tex]
On substituting the given value of KTAS, we get
⇒ [tex]10 \ percent \ of 120+\frac{1}{2} \ of \ the \ number[/tex]
⇒ [tex]12+6[/tex]
⇒ [tex]18 \ degree \ angle \ of \ bank[/tex]
Suppose a student carrying a flu virus returns to an isolated college campus of 9000 students. Determine a differential equation governing the number of students x(t) who have contracted the flu if the rate at which the disease spreads is proportional to the number of interactions between students with the flu and students who have not yet contracted it. (Usek > 0for the constant of proportionality and x forx(t).)
Answer:
dx/dt = kx(9000-x) where k > 0
Explanation:
Number of students in the campus, n = 9000
Number of students who have contracted the flu = x(t) = x
Number of students who have bot yet contracted the flu = 9000 - x
Number of Interactions between those that have contracted the flu and those that are yet to contract it = x(9000 - x)
The rate of spread of the disease = dx/dt
Note: the rate at which the disease spread is proportional to the number of interactions between those that have contracted the flu and those that have not contracted it.
[tex]\frac{dx}{dt} \alpha [x(9000 -x)]\\[/tex]
Introducing a constant of proportionality, k:
dx/dt = kx(9000-x) where k > 0
Consider fully developed laminar flow in a circular pipe. If the viscosity of the fluid is reduced by half by heating while the flow rate is held constant, how will the pressure drop change
Answer:
The pressure drop across the pipe also reduces by half of its initial value if the viscosity of the fluid reduces by half of its original value.
Explanation:
For a fully developed laminar flow in a circular pipe, the flowrate (volumetric) is given by the Hagen-Poiseulle's equation.
Q = π(ΔPR⁴/8μL)
where Q = volumetric flowrate
ΔP = Pressure drop across the pipe
μ = fluid viscosity
L = pipe length
If all the other parameters are kept constant, the pressure drop across the circular pipe is directly proportional to the viscosity of the fluid flowing in the pipe
ΔP = μ(8QL/πR⁴)
ΔP = Kμ
K = (8QL/πR⁴) = constant (for this question)
ΔP = Kμ
K = (ΔP/μ)
So, if the viscosity is halved, the new viscosity (μ₁) will be half of the original viscosity (μ).
μ₁ = (μ/2)
The new pressure drop (ΔP₁) is then
ΔP₁ = Kμ₁ = K(μ/2)
Recall,
K = (ΔP/μ)
ΔP₁ = K(μ/2) = (ΔP/μ) × (μ/2) = (ΔP/2)
Hence, the pressure drop across the pipe also reduces by half of its initial value if the viscosity of the fluid reduces by half of its value.
Hope this Helps!!!
You are given a body with no body forces and told that the stress state is given as: ⎡ ⎣ 3αx 5βx2 + αy γz3 5βx2 + αy βx2 0 γz3 0 5 ⎤ ⎦ psi, where (α, β, γ) are constants with the following values: α = 1 psi/in, β = 1 psi/in2, and γ = 1 psi/in3. Does this represent an equilibrium state of stress? Assume the body occupies the domain Ω = [0, 1] × [0, 1] × [0, 1] (in inches).
Answer:
This doesn't represent an equilibrium state of stress
Explanation:
∝ = 1 , β = 1 , y = 1
x = 0 , y = 0 , z = 0 ( body forces given as 0 )
Attached is the detailed solution is and also the conditions for equilibrium
for a stress state to be equilibrium all three conditions has to meet the equilibrum condition as explained in the attached solution
A square concrete column is 4 in by 4 in cross-section and is subject to a compressive load P. If the compressive stress cannot exceed 4000 psi and the shear stress cannot exceed 1500 psi, the maximum allowable load P is most nearly:
Answer:
64000 lb
Explanation:
A square concrete column is 4 in by 4 in cross-section and is subject to a compressive load P. If the compressive stress cannot exceed 4000 psi and the shear stress cannot exceed 1500 psi.
The area of the square concrete column = 4 in × 4 in = 16 in²
The compressive stress (σ) cannot exceed 4000 psi.
Compressive stress is the ratio of load applied to the area. Therefore the maximum load is the product of the maximum compressive stress and the area. The maximum compressive stress is given as:
[tex]\sigma_{max}=\frac{P_{max}}{Area} \\P_{max}= \sigma_{max}*Area\\P_{max}=4000\ psi *16\ in^2\\P_{max}=64000\ lb[/tex]
Therefore the maximum allowable load P is 64000 lb
A student proposes a complex design for a steam power plant with a high efficiency. The power plant has several turbines, pumps, and feedwater heaters. Steam enters the first turbine at T1 (the highest temperature of the cycle) and saturated liquid exits the condenser at T7 (the lowest temperature of the cycle). The rate of heat transfer to the boiler (the only energy input to the system)is Qb. Determine the maximum possible efficiency and power output for this complex steam power plant design.
Answer:
Hello your question lacks some values here are the values
T1 = 500⁰c, T7 = 70⁰c, Qb = 240000 kj/s
answer : A) 56%
B) 134400 kw ≈ 134.4 Mw
Explanation:
Given values
T1 (tmax) = 500⁰c = 773 k
T7(tmin) = 70⁰c = 343 k
Qb = 240000 kj/s
A) Determine the maximum possible efficiency
[tex]n_{max}[/tex] = 1 - [tex]\frac{tmin}{tmax}[/tex] * 100
= 1 - ( 343 / 773 )
= 1 - 0.44 = 0.5562 * 100 ≈ 56%
B) Determine the power output for this complex steam power plant design
[tex]p_{out}[/tex] = Qb * max efficiency
= 240000 kj/s * 56%
= 240000 * 0.56 = 134400 kw ≈ 134.4 Mw
If a sky diver decides to jump off a jet in Arkansas
with the intention of floating through Tennessee to
North Carolina, then completing his journey in a
likely manner back to Arkansas by drifting North
from his last point. What state would be the third t
be drifted over and what is the estimated distance
between the zone and then drop point?
Answer:
The answer to this question can be defined as follows:
Explanation:
The sky driver began his sky journey from Arkansas, drove across the Tennessee River then landed in North Carolina. He returned to both the north in the very same direction. He began with NC, traveled through Tennessee, eventually lands in Arkansas. But North Carolina has been in the third state on which skydiver was traveling over, and It's also more than 700 miles from Arkansas to the NC.
Many HVACR industry publications are published by
Answer:
HVACR Industry Trade Groups
Explanation:
Tengo un problema con steam y es que sale como que no he comprado un juego pero en realidad si lo he comprado pero por una pagina alterna pero no me lo detecta que hago?
Answer:
Cómo forzar a Steam a reconocer los juegos instalados.
1) Vuelva a instalar los juegos sin descargar.
2) Agregue la carpeta Steam Library manualmente.
3) Reconocer juegos de una nueva unidad
4) Utilizar .acf Cache para forzar el reconocimiento de juegos de Steam .acf Cache para forzar el reconocimiento de juegos de Steam.
Explanation:
1) Vuelva a instalar los juegos sin descargar.
- Inicia Steam y ve a Juegos.
- Seleccione y haga clic en instalar para el juego que Steam no pudo reconocer.
- Steam comenzará a descubrir los archivos existentes para el juego.
2) Agregue la carpeta Steam Library manualmente.
- Lanzar Steam.
- Haga clic en Steam y seleccione Configuración.
- Haz clic en la pestaña Descargas.
- Haga clic en las carpetas de la biblioteca de Steam.
- En la ventana emergente, haz clic en Agregar carpeta de biblioteca y selecciona la ubicación donde se guardan todos los datos de tu juego Steam.
- Haga clic en Seleccionar y cerrar la configuración de Steam.
- Salga de la aplicación Steam y reinicie Steam.
- Steam ahora debería reconocer los juegos instalados nuevamente y enumerarlos en la carpeta de juegos.
3) Reconocer juegos de una nueva unidad
- Inicie la aplicación Steam desde el escritorio.
- Haz clic en Steam y selecciona Configuración.
- Haz clic en la pestaña Descargas.
- Haga clic en la carpeta de la biblioteca de Steam en la sección Bibliotecas de contenido.
- Haga clic en Agregar carpeta de biblioteca y navegue a la ubicación donde se mueven sus juegos (nuevo directorio) que es D: / games / your_subdirectory.
- Haga clic en Seleccionar y cerrar para guardar la carpeta de la biblioteca.
- Salga de Steam y reinícielo.
Steam escaneará la carpeta Biblioteca recientemente seleccionada y mostrará todos los juegos instalados.
4) Utilizar .acf Cache para forzar el reconocimiento de juegos de Steam .acf Cache para forzar el reconocimiento de juegos de Steam.
- Asegúrese de haber reinstalado Steam o tener la instalación existente.
- Mueva los datos del juego a C: >> Archivos de programa (x86) >> Steam >> carpeta Steamapps.
- Lanzar Steam.
- En este punto, Steam puede mostrar algunos juegos que están instalados correctamente.
- Para los juegos que se muestran como no instalados, seleccione y haga clic en el botón Instalar.
- Steam comenzará a descubrir todos los archivos existentes.
- Sin embargo, si Steam no reconoce los archivos existentes, comenzará a descargar los archivos y el progreso leerá 0%.
- Pausa la actualización de los juegos y sal de Steam. Vaya a C: >> Archivos de programa (x86) >> Steam >> Steamapps y encuentre todos los archivos .acf actuales.
¡¡¡Espero que esto ayude!!!
A liquid-liquid extraction process consists of two units, a mixer and a separator. One inlet stream to the mixer consists of two components, species-A and species-B. A stream of pure species-C is fed into the mixer to drive the extraction. The mixture is then fed to a separator where it is allowed to settle into two phases which are removed in separate streams. Each outlet stream contains all three species. The goal of the process is to produce an outlet stream with a high concentration of species-A. Given the data below, perform a degree- of-freedom analysis and determine the order in which systems of equations must be solved to characterize every stream in the process. Then solve the system for all unknown flow rates and compositions.
• One inlet stream to the mixer flows at 100.0 kg/hr and is 35wt% species-A and 65wt% species-B.
• One inlet stream to the mixer is pure species-C, and the flow rate is unknown.
• One outlet stream from the separator is 85wt% species-A and 10wt% species-B.
• One outlet stream from the separator is 25wt% species-B and 70wt% species-C.
Answer:
One inlet stream to the mixer flows at 100.0 kg/hr and is 35wt% species-A and 65wt% species-B.
Explanation:
The process consists of two units, a mixer and a separator. There are three species: A, B, and C.
The goal is to produce an outlet stream with a high concentration of species-A.
How to solveThere are two inlet streams to the mixer. One is 35wt% species-A and 65wt% species-B, and the other is pure species-C. The flow rate of the second stream is unknown.
There are two outlet streams from the separator. One is 85wt% species-A and 10wt% species-B, and the other is 25wt% species-B and 70wt% species-C.
The degree-of-freedom analysis shows that there are 3 equations and 4 unknowns. The order in which the systems of equations must be solved is:
Solve for the flow rate of the stream of pure species-C.
Solve for the compositions of the outlet streams from the separator.
Solve for the compositions of the inlet streams to the mixer.
The solution for all unknown flow rates and compositions is:
The flow rate of the stream of pure species-C is 50.0 kg/hr.
The composition of the outlet stream from the separator that is rich in species-A is 90wt% species-A, 5wt% species-B, and 5wt% species-C.
The composition of the outlet stream from the separator that is rich in species-B is 10wt% species-A, 5wt% species-B, and 85wt% species-C.
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A truss is subjected to three loads. The truss is supported by a roller at A and by a pin joint at B. What is most nearly the reaction force at B
Answer:
Hello the diagram related to the question is missing attached is the diagram
Answer : 3833.33 KN
Explanation:
The most nearly reaction force at B
= ∑ Mb = 0 = 21Ay
= (2000 * 17.5 ) + ( 3000 * 10.5 ) + ( 4000 * 3.5 )
= 35000 + 31500 + 14000 = 80500
therefore Ay = 80500 / 21 = 3833.33 KN
x = 7/2 = 3.5m
In the fully developed region of flow in a circular pipe, does the velocity profile change in the flow direction?
Answer:
No, the velocity profile does not change in the flow direction.
Explanation:
In a fluid flow in a circular pipe, the boundary layer thickness increases in the direction of flow, until it reaches the center of the pipe, and fill the whole pipe. If the density, and other properties of the fluid does not change either by heating or cooling of the pipe, then the velocity profile downstream becomes fully developed, and constant, and does not change in the direction of flow.
A two-dimensional flow field described by
V = (2x^2y + x)1 + (2xy^2 + y + 1 )j
where the velocity is in m/s when x and y are in meters. Determine the angular rotation of a fluid element located at x 0.5 m, y 1.0 m.
Answer:
the answer is
Explanation:
We now focus on purely two-dimensional flows, in which the velocity takes the form u(x, y, t) = u(x, y, t)i + v(x, y, t)j. (2.1) With the velocity given by (2.1), the vorticity takes the form ω = ∇ × u = ∂v ∂x − ∂u ∂y k. (2.2) We assume throughout that the flow is irrotational, i.e. that ∇ × u ≡ 0 and hence ∂v ∂x − ∂u ∂y = 0. (2.3) We have already shown in Section 1 that this condition implies the existence of a velocity potential φ such that u ≡ ∇φ, that is u = ∂φ ∂x, v = ∂φ ∂y . (2.4) We also recall the definition of φ as φ(x, y, t) = φ0(t) + Z x 0 u · dx = φ0(t) + Z x 0 (u dx + v dy), (2.5) where the scalar function φ0(t) is arbitrary, and the value of φ(x, y, t) is independent of the integration path chosen to join the origin 0 to the point x = (x, y). This fact is even easier to establish when we restrict our attention to two dimensions. If we consider two alternative paths, whose union forms a simple closed contour C in the (x, y)-plane, Green’s Theorem implies thatA long conducting rod of rectangular cross section (20 mm 30 mm) and thermal conductivity k 20 W/m K experiences uniform heat generation at a rate q . 5 107 W/m3, while its surfaces are maintained at 300 K. Using a finite-difference method with a grid spacing of 5 mm, determine the temperature distribution in the rod.
Answer:
Explanation:
We are assuming that there is
a steady state two dimensional conduction
constant properties
uniform volumetric heat generation
From symmetry, we will be determining 6 unknown temperatures.
See attachment for calculation and and tabulation
With T(s) = 300 K, the set of equations were written directly into the IHT work space and solved for nodal temperatures.
The result is seen in the second attachment
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 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:
i) Truth Table:
A | B | C | O
0 | 0 | 0 | 0
0 | 0 | 1 | 0
0 | 1 | 0 | 0
0 | 1 | 1 | 0 (condition 2 not satisfied)
1 | 0 | 0 | 0
1 | 0 | 1 | 1 (both conditions satisfied)
1 | 1 | 0 | 1 (both conditions satisfied)
1 | 1 | 1 | 1 (both conditions satisfied)
ii) The minimized sum of products (SOP) expression is
O = AC + AB
Explanation:
We have three inputs A, B and C
Let O is the output.
We are given two conditions to open the vault door:
1. At least two people must insert their keys into the assigned locks at the same time.
2. The trainee bank teller (C) can only open the vault when the bank manager (A) is present in the opening.
i) Construct the Truth Table
A | B | C | O
0 | 0 | 0 | 0
0 | 0 | 1 | 0
0 | 1 | 0 | 0
0 | 1 | 1 | 0 (condition 2 not satisfied)
1 | 0 | 0 | 0
1 | 0 | 1 | 1 (both conditions satisfied)
1 | 1 | 0 | 1 (both conditions satisfied)
1 | 1 | 1 | 1 (both conditions satisfied)
ii) SOP Expression using Karnaugh-Map:
A 3 variable Karnaugh-map is attached.
The minimized sum of products (SOP) expression is
O = AC + AB
The orange pair corresponds to "AC" and the purple pair corresponds to "AB"
Bonus:
The above expression may be realized by using two AND gates and one OR gate.
Please refer to the attached logic circuit diagram.
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:
There is one reservoir filled with water and also connected with one pipe of uniform cross-sectional diameter. Total head at section 1 is 27 m. At section 2, potential head is 3 m, gage pressure is 160 kPa, vvelocity is 4.5 m/s. Find the major head loss at section 2 in unit of m. Round to the nearest one decimal place.
Answer:
6.7 m
Explanation:
Total head at section 1 = 27 m
at section 2;
potential head = 3 m
gauge pressure P = 160 kPa = 160000 Pa
pressure head is gotten as
[tex]Ph =\frac{P}{pg}[/tex]
where p = density of water = 1000 kg/m^3
g = acceleration due to gravity = 9.81 m/^2
[tex]Ph =\frac{160000}{1000 * 9.81} = 16.309 m[/tex]
velocity = 4.5 m/s
velocity head Vh is gotten as
[tex]Vh = \frac{v^{2} }{2g}[/tex]
[tex]Vh = \frac{4.5^{2} }{2*9.81} = 1.03 m[/tex]
obeying Bernoulli's equation,
The total head in section 1 must be equal to the total head in section 2
The total head in section 2 = (potential head) + (velocity head) + (pressure head) + losses(L)
Equating sections 1 and 2, we have
27 = 3 + 1.03 + 16.309 + L
27 = 20.339 + L
L = 27 - 20.339
L = 6.661 ≅ 6.7 m
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.
Read more on Occupational Safety and Health Administration (OSHA) rules at; https://brainly.com/question/17069021
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
Read more on diameter of a wood here:https://brainly.com/question/390660
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 generator operating at 50 Hz delivers 1 pu power to an infinite bus through a transmission circuit in which resistance is ignored. A fault takes place reducing the maximum power transferable to 0.5 pu whereas before the fault, this power was 2.0 pu and after the clearance of the fault, it is 1.5 pu. Using equal area criterion, determine the critical clearing angle.
Answer:
critical clearing angle = 70.3°
Explanation:
Generator operating at = 50 Hz
power delivered = 1 pu
power transferable when there is a fault = 0.5 pu
power transferable before there is a fault = 2.0 pu
power transferable after fault clearance = 1.5 pu
using equal area criterion to determine the critical clearing angle
Attached is the power angle curve diagram and the remaining part of the solution.
The power angle curve is given as
= Pmax sinβ
therefore : 2sinβo = Pm
2sinβo = 1
sinβo = 0.5 pu
βo = [tex]sin^{-1} (0.5) = 30[/tex]⁰
also ; 1.5sinβ1 = 1
sinβ1 = 1/1.5
β1 = [tex]sin^{-1} (\frac{1}{1.5} )[/tex] = 41.81⁰
∴ βmax = 180 - 41.81 = 138.19⁰
attached is the remaining solution
The critical clearing angle = [tex]cos^{-1} 0.3372[/tex] ≈ 70.3⁰
Air flows along a horizontal, curved streamline with a 20 foot radius with a speed of 100 ft/s. Determine the pressure gradient normal to the streamline.
Answer:
- 1.19 lb/ft^3
Explanation:
You are given the following information;
Radius r = 20 ft
Speed V = 100 ft/s
You should use Bernoulli equation pertaining to streamline. That is, normal to streamline.
The pressure gradient = dp/dn
Where air density rho = 0.00238 slugs per cubic foot.
Please find the attached files for the solution and diagram.
Question 44
What should you do if you encounter a fishing boat while out in your vessel?
A
Make a large wake nearby.
B
Avoid making a large wake.
с
Pass on the side with the fishing lines.
D
Pass by close to the anglers.
Submit Answer
Answer:
The answer is B. Avoid making a large wake.
Explanation:
When passing a fishing boat it is important to maintain a minimal wake due to the dangers a large wake could pose to the fishing boat you are passing, it is part of maintaining safety on the water.
You can not pass on the sides with the fishing lines also, and you are supposed to communicate to the fishing boat before taking the appropriate action.
An automobile travels along a straight road at 15.65 m/s through a 11.18 m/s speed zone. A police car observed the automobile. At the instant that the two vehicles are abreast of each other, the police car starts to pursue the automobile at a constant acceleration of 1.96 m/s2 . The motorist noticed the police car in his rear view mirror 12 s after the police car started the pursuit and applied his brakes and decelerates at 3.05 m/s2
An automobile travels along a straight road at 15.65 m/s through a 11.18 m/s speed zone. A police car observed the automobile. At the instant that the two vehicles are abreast of each other, the police car starts to pursue the automobile at a constant acceleration of 1.96 m/s2 . The motorist noticed the police car in his rear view mirror 12 s after the police car started the pursuit and applied his brakes and decelerates at 3.05 m/s2
Find the total time required for the police car to over take the automobile.
Answer:
15.02 sec
Explanation:
The total time required for the police car to overtake the automobile is related to the distance covered by both cars which is equal from instant point of abreast.
So; we can say :
[tex]D_{pursuit} =D_{police}[/tex]
By using the second equation of motion to find the distance S;
[tex]S= ut + \dfrac{1}{2}at^2[/tex]
[tex]D_{pursuit} = (15.65 *12 )+(15.65 (t)+ (\dfrac{1}{2}*(-3.05)t^2)[/tex]
[tex]D_{pursuit} = (187.8)+(15.65 \ t)-0.5*(3.05)t^2)[/tex]
[tex]D_{pursuit} = (187.8+15.65 \ t-1.525 t^2)[/tex]
[tex]D_{police} = ut _P + \dfrac{1}{2}at_p^2[/tex]
where ;
u = 0
[tex]D_{police} = \dfrac{1}{2}at_p^2[/tex]
[tex]D_{police} = \dfrac{1}{2}*(1.96)*(t+12)^2[/tex]
[tex]D_{police} = 0.98*(t+12)^2[/tex]
[tex]D_{police} = 0.98*(t^2 + 144 + 24t)[/tex]
[tex]D_{police} = 0.98t^2 + 141.12 + 23.52t[/tex]
Recall that:
[tex]D_{pursuit} =D_{police}[/tex]
[tex](187.8+15.65 \ t-1.525 t^2)= 0.98t^2 + 141.12 + 23.52t[/tex]
[tex](187.8 - 141.12) + (15.65 \ t - 23.52t) -( 1.525 t^2 - 0.98t^2) = 0[/tex]
= 46.68 - 7.85 t -2.505 t² = 0
Solving by using quadratic equation;
t = -6.16 OR t = 3.02
Since we can only take consideration of the value with a positive integer only; then t = 3.02 secs
From the question; The motorist noticed the police car in his rear view mirror 12 s after the police car started the pursuit;
Therefore ; the total time required for the police car to over take the automobile = 12 s + 3.02 s
Total time required for the police car to over take the automobile = 15.02 sec
For laminar flow over a hot flat plate, the local heat transfer coefficient decreases with distance because (select all that are correct
Answer:
hello the answer options are missing here are the options
A)The thickness of the heated region near the plate is increasing
B)The velocities near the plates are increasing
C)The fluid temperature near the plate are increasing
ANSWER : all of the above
Explanation:
Laminar flow is the flow of a type of fluid across the surface of an object following regular paths and it is unlike a turbulent flow which flows in irregular paths (encountering fluctuations)
For laminar flow over a hot flat plate, the local heat transfer coefficient decreases with distance because :
The thickness of the heated region near the plate is increasingThe velocities near the plates are increasingThe fluid temperature near the plate are increasingA thermal energy storage unit consists of a large rectangular channel, which is well insulated on its outer surface and encloses alternating layers of the storage material and the flow passage. Each layer of the storage material is an aluminum slab of width W=0.05 m, which is at an initial temperature of 25∘C25 ∘C. Consider conditions for which the storage unit is charged by passing a hot gas through the passages, with the gas temperature and the convection coefficient assumed to have constant values of T[infinity]=600∘CT [infinity]=600 ∘C and h=100W/m2⋅Kh=100W/m 2⋅K throughout the channel. How long will it take to achieve 75% of the maximum possible energy storage? What is the temperature of the aluminum at this time?
Answer:
the temperature of the aluminum at this time is 456.25° C
Explanation:
Given that:
width w of the aluminium slab = 0.05 m
the initial temperature [tex]T_1[/tex] = 25° C
[tex]T{\infty} =600^0C[/tex]
h = 100 W/m²
The properties of Aluminium at temperature of 600° C by considering the conditions for which the storage unit is charged; we have ;
density ρ = 2702 kg/m³
thermal conductivity k = 231 W/m.K
Specific heat c = 1033 J/Kg.K
Let's first find the Biot Number Bi which can be expressed by the equation:
[tex]Bi = \dfrac{hL_c}{k} \\ \\ Bi = \dfrac{h \dfrac{w}{2}}{k}[/tex]
[tex]Bi = \dfrac{hL_c}{k} \\ \\ Bi = \dfrac{100 \times \dfrac{0.05}{2}}{231}[/tex]
[tex]Bi = \dfrac{2.5}{231}[/tex]
Bi = 0.0108
The time constant value [tex]\tau_t[/tex] is :
[tex]\tau_t = \dfrac{pL_cc}{h} \\ \\ \tau_t = \dfrac{p \dfrac{w}{2}c}{h}[/tex]
[tex]\tau_t = \dfrac{2702* \dfrac{0.05}{2}*1033}{100}[/tex]
[tex]\tau_t = \dfrac{2702* 0.025*1033}{100}[/tex]
[tex]\tau_t = 697.79[/tex]
Considering Lumped capacitance analysis since value for Bi is less than 1
Then;
[tex]Q= (pVc)\theta_1 [1-e^{\dfrac {-t}{ \tau_1}}][/tex]
where;
[tex]Q = -\Delta E _{st}[/tex] which correlates with the change in the internal energy of the solid.
So;
[tex]Q= (pVc)\theta_1 [1-e^{\dfrac {-t}{ \tau_1}}]= -\Delta E _{st}[/tex]
The maximum value for the change in the internal energy of the solid is :
[tex](pVc)\theta_1 = -\Delta E _{st}max[/tex]
By equating the two previous equation together ; we have:
[tex]\dfrac{-\Delta E _{st}}{\Delta E _{st}{max}}= \dfrac{ (pVc)\theta_1 [1-e^{\dfrac {-t}{ \tau_1}}]} { (pVc)\theta_1}[/tex]
Similarly; we need to understand that the ratio of the energy storage to the maximum possible energy storage = 0.75
Thus;
[tex]0.75= [1-e^{\dfrac {-t}{ \tau_1}}]}[/tex]
So;
[tex]0.75= [1-e^{\dfrac {-t}{ 697.79}}]}[/tex]
[tex]1-0.75= [e^{\dfrac {-t}{ 697.79}}]}[/tex]
[tex]0.25 = e^{\dfrac {-t}{ 697.79}}[/tex]
[tex]In(0.25) = {\dfrac {-t}{ 697.79}}[/tex]
[tex]-1.386294361= \dfrac{-t}{697.79}[/tex]
t = 1.386294361 × 697.79
t = 967.34 s
Finally; the temperature of Aluminium is determined as follows;
[tex]\dfrac{T - T _{\infty}}{T_1-T_{\infty}}= e ^ {\dfrac{-t}{\tau_t}}[/tex]
[tex]\dfrac{T - 600}{25-600}= e ^ {\dfrac{-967.34}{697.79}[/tex]
[tex]\dfrac{T - 600}{25-600}= 0.25[/tex]
[tex]\dfrac{T - 600}{-575}= 0.25[/tex]
T - 600 = -575 × 0.25
T - 600 = -143.75
T = -143.75 + 600
T = 456.25° C
Hence; the temperature of the aluminum at this time is 456.25° C
Instructions given by traffic police or construction flaggers _____. A. Are sometimes important to follow B. Are usually not important to follow C. Don't overrule laws or traffic control devices D. Overrule any other laws and traffic control devices
Answer:
D. Overrule any other laws and traffic control devices.
Explanation:
Laws and traffic control devices are undoubtedly compulsory to be followed at every point in time to control traffic and other related situations. However, there are cases when certain instructions overrule these laws and traffic control devices. For example, when a traffic police is giving instructions, and though the traffic control devices too (such as traffic lights) are displaying their own preset lights to control some traffic, the instructions from the traffic police take more priority. This is because at that point in time, the instructions from the traffic control devices might not be just applicable or sufficient.
Also, in the case of instructions given by construction flaggers, these instructions have priority over those from controlling devices. This is because during construction traffic controls are redirected from the norms. Therefore, the flaggers such be given more importance.
Answer:
D. Overrule any other laws and traffic control devices.
Explanation:
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.
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
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.
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Hope this helps!
Brainliest would be great!
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With all care,
07x12!