Answer:
The question is incomplete, the complete question is:
Which of the following is not a reason to give yourself extra "cushion" when driving?
A. Poor visibility B. Poor road conditions C. Inclement weather D. None of these.
The correct answer is D. None of these.
Explanation:
All the options are not reasons to give yourself an extra cushion when driving, rather they are reasons that are not favorable to driving at all.
A cushion is a certain amount of distance you are supposed to keep between you and the car in front of you to allow easy maneuvering in any condition.
A typical cushion is 3 seconds between you and the car in front of you, in less than perfect conditions like bad weather or poor road conditions an additional second must be added to it.
A steady 4.0-lb force is applied normal to the handle of the hand-operated grinder. The gear inside the housing with its shaft and attached handle together weigh 4.26 lb and have a radius of gyration about their axis of 2.97 in. The grinding wheel with its attached shaft and pinion (inside housing) together weigh 1.07 lb and have a radius of gyration of 1.95 in. If the gear ratio between gear and pinion is 5:1, calculate the speed N (in revolutions/min) of the grinding wheel after 5 complete revolutions of the handle starting from rest.
Answer:
the speed N of the grinding wheel after 5 complete revolutions of the handle starting from rest is 3122.62 rev/min
Explanation:
From the given information ;
According to the principles of Conservation of energy;
[tex]M \Theta =(\dfrac{1}{2}I_{gh} \omega_1^2)_{gear \ housing} +( \dfrac{1}{2} I_{ph} \omega^2)_{pinion \ housing}[/tex]
where;
[tex]M \Theta =[/tex] gain in potential energy as a result of restoring friction
[tex](\dfrac{1}{2}I_{gh} \omega_1^2)_{gear \ housing}[/tex] = kinetic energy as a result of rotation of the gear housing
[tex](\dfrac{1}{2} I_{ph} \omega^2)_{pinion \ housing}[/tex] = Kinetic energy as a result of rotation of pinion housing
However; the equation can be re-written as:
[tex]F*I* \Theta =(\dfrac{1}{2}*(mr^2)* \omega_1^2)_{gear \ housing} +( \dfrac{1}{2} *(mr^2)*\omega^2)_{pinion \ housing}[/tex]
where;
F = restoring Force
I = mass moment of the inertia
r = radius of gyration
Let assume the mass moment of inertia is 6.0 In around the the handle of the hand-operated grinder, since it is not given and a diagram is not attached ;
NOW;
[tex]4.0*\dfrac{6.0}{12}*5*2 \pi =[ (\dfrac{1}{2}*(\dfrac{4.26}{32.2})*(\dfrac{2.97}{12})^2*(\dfrac{\omega}{5})^2+( \dfrac{1}{2})*(\dfrac{1.07}{33.2}) *(\dfrac{1.95}{12})^2* \omega ^2)][/tex]
62.83 = [tex]1.6208*10^{-4} \omega^2 + 4.255*10^{-4} \omega^2[/tex]
62.83 = [tex]5.8758*10^{-4} \ \omega^2[/tex]
[tex]\omega^2 = \dfrac{62.83}{5.8758*10^{-4} }[/tex]
[tex]\omega^{2}= 106930.12 \\ \\ \omega = \sqrt{106930.12}[/tex]
[tex]\omega = 327 \ rad/s[/tex]
The spinning of the wheel is [tex]\omega = \dfrac{2 \pi N}{60}[/tex]
[tex]N = \dfrac{\omega *60}{2 \pi}[/tex]
[tex]N = \dfrac{327 *60}{2 \pi}[/tex]
N = 3122.62 rev/min
Thus; the speed N of the grinding wheel after 5 complete revolutions of the handle starting from rest is 3122.62 rev/min
A photograph of the NASA Apollo 16 Lunar Module (abbreviated by NASA as the LM is shown on the surface of the Moon. Such spacecraft made six Moon landings during 1,969 - 72. A simplified model for one of the four landing gear assemblies of the LM is shown. If the LM has 13,500 kg mass, and rests on the surface of the Moon where acceleration due to gravity is 1.82 m/s^2, determine the force supported by members AB, AC, and AD. Assume the weight of the LM is uniformly supported by all four landing gear assemblies, and neglect friction between the landing gear and the surface of the Moon. TAB =N TAC = TAD =N A ( 2.6, 2.6, -2.2 ) m B(1.5, 1.5, 0)m C(2,1,-1.2)m D(1,2,-1.2)m
Answer:
[tex]\mathbf{F_{AB} = 13785.06 N }[/tex]
[tex]\mathbf{F_{AC} = -5062.38 N }[/tex]
[tex]\mathbf{F_{AD} = -5062.38 N }[/tex]
Explanation:
From the given information:
Let calculate the position vector of AB, AC, and AD
To start with AB; in order to calculate the position vector of AB ; we have:
[tex]r_{AB}^{\to} = r _{OA}^{\to} - r_{OB}^{\to} \\ \\ r_{AB}^{\to} = (2.6 \ \hat i + 2.6 \ \hat j - 2.2 \ \hat k ) - ( 1.5 \ \hat i + \ 1. 5 \hat j ) \\ \\ r_{AB}^{\to} = ( 2.6 \ \hat i - 1.5 \ \hat i + 2.6 \ \hat j - 1.5 \ \hat j - 2.2 \ \hat k) \\ \\ r_{AB}^{\to} = (1.1 \ \hat i + 1.1 \ \hat j - 2.2 \ \hat k ) m[/tex]
To calculate the position vector of AC; we have:
[tex]r_{AC}^{\to} = r _{OA}^{\to} - r_{OC}^{\to} \\ \\ r_{AC}^{\to} = (2.6 \ \hat i + 2.6 \ \hat j - 2.2 \ \hat k ) - ( 2\ \hat i + \ \hat j - 1.2 \ \hat k) \\ \\ r_{AC}^{\to} = ( 2.6 \ \hat i - 2\ \hat i + 2.6 \ \hat j - \ \hat j - 2.2 \ \hat k + 1.2 \ \hat k) \\ \\ r_{AC}^{\to} = (0.6 \ \hat i + 1.6 \ \hat j - \ \hat k ) m[/tex]
To calculate the position vector of AD ; we have:
[tex]r_{AD}^{\to} = r _{OA}^{\to} - r_{OD}^{\to} \\ \\ r_{AC}^{\to} = (2.6 \ \hat i + 2.6 \ \hat j - 2.2 \ \hat k ) - ( \hat i + \ 2 \hat j - 1.2 \ \hat k) \\ \\ r_{AD}^{\to} = ( 2.6 \ \hat i - \hat i + 2.6 \ \hat j - 2 \ \hat j - 2.2 \ \hat k + 1.2 \ \hat k) \\ \\ r_{AD}^{\to} = (1.6 \ \hat i + 0.6 \ \hat j - \ \hat k ) m[/tex]
However; let's calculate the force in AB, AC and AD in their respective unit vector form;
To start with unit vector AB by using the following expression; we have:
[tex]F_{AB}^{\to} = F_{AB} \dfrac{ r _{AB}^{\to} }{|r_{AB}^{\to}} \\ \\ \\ F_{AB}^{\to} = F_{AB} \dfrac{(1.1 \ \hat i + 1.1 \ \hat j - 2.2 \ \hat k ) }{\sqrt{ (1.1)^2 + (1.1)^2 + (-2.2 )^2 }} \\ \\ \\ F_{AB}^{\to} = F_{AB} \dfrac{(1.1 \ \hat i + 1.1 \ \hat j - 2.2 \ \hat k ) }{ \sqrt{7.26}} \\ \\ \\ F_{AB}^{\to} = F_{AB} \dfrac{(1.1 \ \hat i + 1.1 \ \hat j - 2.2 \ \hat k ) }{ 2.6944} \\ \\ \\ F_{AB}^{\to} = F_{AB} (0.408 \ \hat i+ 0.408 \ \hat j - 0.8165 \ \hat k ) N\\[/tex]
The force AC in unit vector form is ;
[tex]F_{AC}^{\to} = F_{AC} \dfrac{ r _{AC}^{\to} }{|r_{AC}^{\to}} \\ \\ \\ F_{AC}^{\to} = F_{AC} \dfrac{(0.6 \ \hat i + 1.6 \ \hat j - \ \hat k ) }{\sqrt{ (0.6)^2 + (1.6)^2 + (-1 )^2 }} \\ \\ \\ F_{AC}^{\to} = F_{AC} \dfrac{(0.6 \ \hat i + 1.6 \ \hat j - \ \hat k ) }{ \sqrt{3.92}} \\ \\ \\ F_{AC}^{\to} = F_{AC} \dfrac{(0.6 \ \hat i + 1.6 \ \hat j - \ \hat k ) }{1.9798} \\ \\ \\ F_{AC}^{\to} = F_{AC} (0.303 \ \hat i+ 0.808 \ \hat j - 0.505 \ \hat k ) N\\[/tex]
The force AD in unit vector form is ;
[tex]F_{AD}^{\to} = F_{AD} \dfrac{ r _{AD}^{\to} }{|r_{AD}^{\to}|} \\ \\ \\ F_{AD}^{\to} = F_{AD} \dfrac{(1.6 \ \hat i + 0.6 \ \hat j - \ \hat k ) }{\sqrt{ (1.6)^2 + (0.6)^2 + (-1 )^2 }} \\ \\ \\ F_{AD}^{\to} = F_{AD} \dfrac{(1.6 \ \hat i + 0.6 \ \hat j - \ \hat k ) }{ \sqrt{3.92}} \\ \\ \\ F_{AD}^{\to} = F_{AD} \dfrac{(1.6 \ \hat i + 0.6 \ \hat j - \ \hat k ) }{1.9798} \\ \\ \\ F_{AD}^{\to} = F_{AD} (0.808 \ \hat i+ 0.303 \ \hat j - 0.505 \ \hat k ) N\\[/tex]
Similarly ; the weight of the lunar Module is:
W = mg
where;
mass = 13500 kg
acceleration due to gravity= 1.82 m/s²
W = 13500 × 1.82
W = 24,570 N
Also. we known that the load is shared by four landing gears; Thus, the vertical reaction force exerted by the ground on each landing gear can be expressed as:
[tex]R =\dfrac{W}{4}[/tex]
[tex]R =\dfrac{24,570}{4}[/tex]
R = 6142.5 N
Now; the reaction force at point A in unit vector form is :
[tex]R^{\to} = Rk^{\to} \\ \\ R^{\to} = (6142.5 \ k ^{\to}) \ N[/tex]
Using the force equilibrium at the meeting point of the coordinates at A.
[tex]\sum F^{\to} = 0[/tex]
[tex]F_{AB}^{\to} +F_{AC}^{\to} + F_{AD}^{\to} + R^{\to} =0[/tex]
[tex][F_{AB} (0.408 \ \hat i + 0.408 \ \hat j - 0.8165 \ \hat k ) N + F_{AC} (0.303 \ \hat i + 0.808 \ \hat j - 0.505 \ \hat k ) N + F_{AD} (0.808 \ \hat i + 0.303 \ \hat j - 0.505 \ \hat k) N + (6142.5 \ k^ \to ) ][/tex]
[tex]= [ ( 0.408 F_{AB} +0.303 F_{AC} + 0.808F_{AD}) \hat i + (0.408 F_{AB}+0.808F_{AC}+0.303F_{AD}) \hat j + (-0.8165 F_{AB} -0.505F_{AC} -0.505 F_{AD} +6142.5 ) k ^ \to ] = 0[/tex]
From above; we need to relate and equate each coefficients i.e i ,j, and [tex]k ^ \to[/tex] on both sides ; so, we can re-write that above as;
[tex]0.408 F_{AB} +0.303 F_{AC} + 0.808F_{AD}) =0 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ --- (1) \\ \\ 0.408 F_{AB}+0.808F_{AC}+0.303F_{AD}) =0 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ --- (2) \\ \\ -0.8165 F_{AB} -0.505F_{AC} -0.505 F_{AD} +6142.5 = 0 --- (3)[/tex]
Making rearrangement and solving by elimination method;
[tex]\mathbf{F_{AB} = 13785.06 N }[/tex]
[tex]\mathbf{F_{AC} = -5062.38 N }[/tex]
[tex]\mathbf{F_{AD} = -5062.38 N }[/tex]
The force vector of each member, depends on the magnitude of the
force and the unit vector of the member.
Responses:
The force supported by the members are;
Force supported by AB is; 13,799.95 NForce supported by AC is; -5070.2 NForce supported by AD is -5070.2 NHow can the unit vector of each member give their force?Resolving the given members into unit vectors gives;
[tex]\hat u_{AB} = \mathbf{\dfrac{(2.6 - 1.5) \cdot \hat i + (2.6 - 1.5)\cdot \hat j + (-2.2)\cdot \hat k }{\sqrt{(2.6- 1.5)^2 + (2.6 - 1.5)^2 + (-2.2)^2}}}[/tex][tex]\dfrac{(2.6 - 1.5) \cdot \hat i + (2.6 - 1.5)\cdot \hat j + (-2.2)\cdot \hat k }{\sqrt{(2.6- 1.5)^2 + (2.6 - 1.5)^2 + (-2.2)^2}}= 0.40825 \cdot \hat i + 0.40825\cdot \hat j - 0.81625\cdot \hat k[/tex]
[tex]\hat u_{AB} = \mathbf{0.40825 \cdot \hat i + 0.40825\cdot \hat j - 0.81625\cdot \hat k}[/tex]Similarly, we have;
[tex]\hat u_{AC} =\mathbf{ \dfrac{(2.6 - 2) \cdot \hat i + (2.6 - 1)\cdot \hat j + (-2.2+1.2)\cdot \hat k }{\sqrt{(2.6- 2)^2 + (2.6 - 1)^2 + (-2.2+1.2)^2}}}[/tex]
[tex]\dfrac{(2.6 - 2) \cdot \hat i + (2.6 - 1)\cdot \hat j + (-2.2+1.2)\cdot \hat k }{\sqrt{(2.6- 2)^2 + (2.6 - 1)^2 + (-2.2+1.2)^2}} =\dfrac{0.6\cdot \hat i +1.6\cdot \hat j -1\cdot \hat k }{\sqrt{0.6^2 + 1.6^2 + (-1.)^2}}[/tex]
[tex]\dfrac{0.6\cdot \hat i +1.6\cdot \hat j -1\cdot \hat k }{\sqrt{0.6^2 + 1.6^2 + (-1.)^2}}= 0.303046\cdot \hat i + 0.80812\cdot \hat j - 0.50508\cdot \hat k[/tex]
[tex]\hat u_{AC} =\mathbf{0.303046\cdot \hat i + 0.80812\cdot \hat j - 0.50508\cdot \hat k}[/tex][tex]\hat u_{AD} =\mathbf{ \dfrac{(2.6 - 1) \cdot \hat i + (2.6 -2)\cdot \hat j + (-2.2 + 1.2)\cdot \hat k }{\sqrt{(2.6-1)^2 + (2.6 -2))^2 + (-2.2 + 1.2)^2}}}[/tex]
[tex]\hat u_{AD} =\mathbf{0.80812\cdot \hat i+ 0.303046\cdot \hat j - 0.50508\cdot \hat k}[/tex]
The forces are therefore;
[tex]\vec F_{AB} =\mathbf{ F_{AB} \cdot \left ( 0.40825 \cdot \hat i + 0.40825\cdot \hat j - 0.81625\cdot \hat k \right)}[/tex]
[tex]\vec F_{AC} =\mathbf{ F_{AC} \cdot \left (0.303046\cdot \hat i + 0.80812\cdot \hat j - 0.50508\cdot \hat k\right)}[/tex]
[tex]\vec F_{AD} = \mathbf{F_{AD} \cdot \left (0.80812\cdot \hat i+ 0.303046\cdot \hat j - 0.50508\cdot \hat k\right)}[/tex]
[tex]Weight \ on \ the \ assembly = \dfrac{13,500 \, kg \times 1.82 \, m/s^2}{4} = 6,142.5 \, \hat k N[/tex]
Which gives;
[tex]\mathbf{0.40825 \cdot \hat i \cdot F_{AB}}[/tex] + [tex]0.303046\cdot \hat i \cdot F_{AC}[/tex] + [tex]0.80812\cdot \hat i \cdot F_{AD}[/tex] = 0
[tex]0.40825 \cdot \hat j \cdot F_{AB}[/tex] + [tex]0.80812\cdot \hat j \cdot F_{AC}[/tex] + [tex]0.303046 \cdot \hat j \cdot F_{AD}\left[/tex] = 0
[tex]-0.81625\cdot \hat k \cdot F_{AB}[/tex] - [tex]0.50508\cdot \hat k \cdot F_{AC}[/tex] - [tex]0.50508\cdot \hat k \cdot F_{AD}[/tex] + [tex]\mathbf{6,142.5 \, \hat k}[/tex] = 0
Which gives;
[tex]-0.81625\cdot \hat k \cdot F_{AB}[/tex] - [tex]0.50508\cdot \hat k \cdot F_{AC}[/tex] - [tex]0.50508\cdot \hat k \cdot F_{AD}[/tex] = [tex]-6,142.5 \, \hat k[/tex]
Solving gives;
[tex]F_{AB}[/tex] = 13799.95 N[tex]F_{AC}[/tex] = -5070.2 N[tex]F_{AD}[/tex] = -5070.2 NLearn more about unit vectors here:
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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.
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 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
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
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.
The rectangular frame is composed of four perimeter two-force members and two cables AC and BD which are incapable of supporting compression. Determine the forces in all members due to the load L in position (a) and then in position (b). Forces are positive if in tension, negative if in compression.
Answer:
Your question is lacking some information attached is the missing part and the solution
A) AB = AD = BD = 0, BC = LC
AC = [tex]\frac{5L}{3}T, CD = \frac{4L}{3} C[/tex]
B) AB = AD = BC = BD = 0
AC = [tex]\frac{5L}{3} T, CD = \frac{4L}{3} C[/tex]
Explanation:
A) Forces in all members due to the load L in position A
assuming that BD goes slack from an inspection of Joint B
AB = 0 and BC = LC from Joint D, AD = 0 and CD = 4L/3 C
B) steps to arrive to the answer is attached below
AB = AD = BC = BD = 0
AC = [tex]\frac{5L}{3} T, CD = \frac{4L}{3}C[/tex]
Water vapor at 10bar, 360°C enters a turbine operatingat steady state with a volumetric flow rate of 0.8m3/s and expandsadiabatically to an exit state of 1 bar, 160°C. Kinetic and potentialenergy effects are negligible. Determine for the turbine (a) the powerdeveloped, in kW, (b) the rate of entropy production, in kW/K, and (c)the isentropic turbine efficiency
Answer:
A) W' = 178.568 KW
B) ΔS = 2.6367 KW/k
C) η = 0.3
Explanation:
We are given;
Temperature at state 1;T1 = 360 °C
Temperature at state 2;T2 = 160 °C
Pressure at state 1;P1 = 10 bar
Pressure at State 2;P2 = 1 bar
Volumetric flow rate;V' = 0.8 m³/s
A) From table A-6 attached and by interpolation at temperature of 360°C and Pressure of 10 bar, we have;
Specific volume;v1 = 0.287322 m³/kg
Mass flow rate of water vapour at turbine is defined by the formula;
m' = V'/v1
So; m' = 0.8/0.287322
m' = 2.784 kg/s
Now, From table A-6 attached and by interpolation at state 1 with temperature of 360°C and Pressure of 10 bar, we have;
Specific enthalpy;h1 = 3179.46 KJ/kg
Now, From table A-6 attached and by interpolation at state 2 with temperature of 160°C and Pressure of 1 bar, we have;
Specific enthalpy;h2 = 3115.32 KJ/kg
Now, since stray heat transfer is neglected at turbine, we have;
-W' = m'[(h2 - h1) + ((V2)² - (V1)²)/2 + g(z2 - z1)]
Potential and kinetic energy can be neglected and so we have;
-W' = m'(h2 - h1)
Plugging in relevant values, the work of the turbine is;
W' = -2.784(3115.32 - 3179.46)
W' = 178.568 KW
B) Still From table A-6 attached and by interpolation at state 1 with temperature of 360°C and Pressure of 10 bar, we have;
Specific entropy: s1 = 7.3357 KJ/Kg.k
Still from table A-6 attached and by interpolation at state 2 with temperature of 160°C and Pressure of 1 bar, we have;
Specific entropy; s2 = 8.2828 KJ/kg.k
The amount of entropy produced is defined by;
ΔS = m'(s2 - s1)
ΔS = 2.784(8.2828 - 7.3357)
ΔS = 2.6367 KW/k
C) Still from table A-6 attached and by interpolation at state 2 with s2 = s2s = 8.2828 KJ/kg.k and Pressure of 1 bar, we have;
h2s = 2966.14 KJ/Kg
Energy equation for turbine at ideal process is defined as;
Q' - W' = m'[(h2 - h1) + ((V2)² - (V1)²)/2 + g(z2 - z1)]
Again, Potential and kinetic energy can be neglected and so we have;
-W' = m'(h2s - h1)
W' = -2.784(2966.14 - 3179.46)
W' = 593.88 KW
the isentropic turbine efficiency is defined as;
η = W_actual/W_ideal
η = 178.568/593.88 = 0.3
Trade-offs can be necessary at any point in time during the life cycle of a project. It is quite possible, and probable, for the criteria for the trade-offs to change over the life cycle of the project. Please also identifies how the relative importance of constraints of time, cost, and performance can change over the life cycle of the project.
Answer:
According to the Principles of Project management, the three factors which dominate the lifecycle of any project are:
Time;Cost; andPerformance.The relationship between the three is usually governed by trade-offs.
Explanation:
In simple term, in executing a project, one must deal with the factors mentioned above.
It is always desirous for a project to be finished within a stipulated time. If the time required is reduced inconsiderably, it will most likely incur more cost and even impact performance.
On the other hand, if the project is cost-sensitive and is executed to a very minimalistic budget, performance will be impacted and it may take a protracted amount of time.
In addition to the above, if the principal decides to change the original design of the project, the performance expected is altered. This will attract additional time as well as cost.
It is possible for any of the above factors to be renegotiated and readjusted at any time during the project. It usually is a trade-off.. that is one for the other.
Cheers!
In real world, sampling and quantization is performed in an analog to digital converter (ADC) and reconstruction is performed in a digital to analog converter (DAC). Which of the following statements hold true (fs denotes the sampling frequency)?
a. the reconstruction filter can be found in the DAQ
b. the antialiasing filter removes all frequencies of the continuous-time analog input signal that are above fs/2
c. the DAC needs to know the sampling frequency of the ADC to correctly reconstruct the signal.
d. the reconstructed continuous-time signal only contains frequencies up to fs/2
Answer:
b
Explanation:
a) ADC is located on DAQ filter but not the reconstruction filter
b) to remove aliasing, the sampling rate must be greater than or equal ot twice the highest frequency component in the input signal. In other words, all frequencies in input sgnal are less than fs/2. Therefore, frequencies greater than fs/2 are removed by anti-aliasing filter
c) the DAC can have different sampling rate from ADC
Air enters a compressor operating at steady state at 176.4 lbf/in.^2, 260°F with a volumetric flow rate of 424 ft^3/min and exits at 15.4 lbf/in.^2, 80°F. Heat transfer occurs at a rate of 6800 Btu/h from the compressor to its surroundings. Assuming the ideal gas model for air and neglecting kinetic and potential energy effects, determine the power input, in hp
Answer:
[tex]W_s =[/tex] 283.181 hp
Explanation:
Given that:
Air enters a compressor operating at steady state at a pressure [tex]P_1[/tex] = 176.4 lbf/in.^2 and Temperature [tex]T_1[/tex] at 260°F
Volumetric flow rate V = 424 ft^3/min
Air exits at a pressure [tex]P_2[/tex] = 15.4 lbf/in.^2 and Temperature [tex]T_2[/tex] at 80°F.
Heat transfer occurs at a rate of 6800 Btu/h from the compressor to its surroundings; since heat is released to the surrounding; then:
[tex]Q_{cv}[/tex] = -6800 Btu/h = - 1.9924 kW
Using the steady state energy in the process;
[tex]h_2 - h_1 + g(z_2-z_1)+ \dfrac{1}{2}(v^2_2-v_1^2) = \dfrac{Q_{cv}}{m}- \dfrac{W_s}{m}[/tex]
where;
[tex]g(z_2-z_1) =0[/tex] and [tex]\dfrac{1}{2}(v^2_2-v_1^2) = 0[/tex]
Then; we have :
[tex]h_2 - h_1 = \dfrac{Q_{cv}}{m}- \dfrac{W_s}{m}[/tex]
[tex]h_2 - h_1 = \dfrac{Q_{cv} - W_s}{m}[/tex]
[tex]{m}(h_2 - h_1) ={Q_{cv} - W_s}[/tex]
[tex]W_s ={Q_{cv} + {m}(h_2 - h_1)[/tex] ----- (1)
Using the relation of Ideal gas equation;
P₁V₁ = mRT₁
Pressure [tex]P_1[/tex] = 176.4 lbf/in.^2 = ( 176.4 × 6894.76 ) N/m² = 1216235.664 N/m²
Volumetric flow rate V = 424 ft^3/min = (424 × 0.0004719) m³ /sec
= 0.2000856 m³ /sec
Temperature = 260°F = (260°F − 32) × 5/9 + 273.15 = 399.817 K
Gas constant R=287 J/kg K
Then;
1216235.664 N/m² × 0.2000856 m³ /sec = m × 287 J/kg K × 399.817 K
[tex]m = \dfrac { 1216235.664 N/m^2 \times 0.2000856 m^3 /sec } {287 J/kg K \times 399.817 K }[/tex]
m = 2.121 kg/sec
The change in enthalpy:
[tex]m(h_1-h_2) = m * C_p * \Delta T= m* C_p * ( T_1 -T_2)[/tex]
[tex]= 2.121* 1.005* ( 399.817 -299.817)[/tex]
= 213.1605 kW
From (1)
[tex]W_s ={Q_{cv} + {m}(h_2 - h_1)[/tex]
[tex]W_s =[/tex] - 1.9924 kW + 213.1605 kW
[tex]W_s =[/tex] 211.1681 kW
[tex]W_s =[/tex] 283.181 hp
The power input is [tex]W_s =[/tex] 283.181 hp
If the resistance reading on a DMM'S meter face is to 22.5 ohms in the range selector switch is set to R X 100 range, what is the actual measure resistance of the circuit?
Answer:
The answer is 2.25 kΩ
Explanation:
Solution
Given that:
The resistance reading on a DMM'S meter face = 22.5 ohms
The range selector switch = R * 100 range,
We now have to find the actual measure resistance of the circuit which is given below:
The actual measured resistance of the circuit is=R * 100
= 22.5 * 100
=2.25 kΩ
Hence the measured resistance of the circuit is 2.25 kΩ
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
A 3-phase, 50 Hz, 110 KV overhead line has conductors placed in a horizontal plane 3 m apart. Conductor diameter is 2.5 cm. If the line length is 220 km, determine the charging current per phase assuming complete transposition. (6 Marks)
Answer:
A 3-phase, 50 Hz, 110 KV overhead line has conductors
Explanation:
hope it will helps you
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 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
Technician A says that clutch slippage can be a result of excessively strong pressure plate spring(s). Technician B says that when replacing the friction disc, it is good practice to also replace the pressure plate. Who is correct?
Answer:
Both Technicians are correct.
Explanation:
Anything that increases the workload on the clutch (such as towing, hauling and racing the) also exacerbates wear and eventually lead to slippage. It is a given fact that the clutch plate in most vehicles with a manual transmission wears out faster than any other component of the vehicle the need to replace as often as required.
Technician B's position is right because it takes a lot of effort to replace a clutch so it makes sense (in terms and time and money) to replace everything at once so that one doesn’t have to replace something else later on. It may be that it will cost almost the same amount in man-hours to fix both components.
Cheers!
A 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
With 10,000 per day who would be the apparent low bidder; Bidder A was $500,000 and estimated completion date of 200 days. Bidder B was $540,000 and a completion day and estimated completion date of 180.
1. Bidder B
2. Bidder A
Answer:
Bidder B is the lower bidder. the option (A) is correct
Explanation:
Solution
Given that:
Bidder A = $500,000
The estimate completion time = 200 days
Bidder B = $540,000
The estimate completion time =180 days
Overhead charges = $10,000/day
Now,
The Total Bid of A (including overhead charges) = 500,000 + 200 * 10000
= 500,000 +2000000
=$2,500,000
The Total Bid for B (Including overhead charges) = 540,000 + 180 * 10000
=540,000 +1,800,000
=$2340000
Hence Bidder B is apparently a low bidder, since the Total Bid of B is lower than the Total Bid of A.
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.
Read more about flow rate here:
https://brainly.com/question/31070366
#SPJ2
3. (9 points) A square-thread power screw is used to raise or lower the basketball board in a gym, the weight of which is W = 100kg. See the following two figures. For power screws, assume a major diameter d = 20mm, and a pitch of p = 2mm with double threads. The friction coefficient of steel parts is f = 0.1. Gravity constant is g = 10????/kg. (a) (7 points) If the purchased Cordless Electric Power Screwdrivers rotates at 300rpm, determine the power you need to raise to the basket board. (b) (2 points) Check if the self-locking condition of the power screw is satisfied or not.
Answer:
a) 49.95 watts
b) The self locking condition is satisfied
Explanation:
Given data
weight of the square-thread power screw ( w ) = 100 kg = 1000 N
diameter (d) = 20 mm ,
pitch (p) = 2 mm
friction coefficient of steel parts ( f ) = 0.1
Gravity constant ( g ) = 10 N/kg
Rotation of electric power screwdrivers = 300 rpm
A ) Determine the power needed to raise to the basket board
first we have to calculate T
T = Wtan (∝ + Ф ) * [tex]\frac{Dm}{2}[/tex] ------------- equation 1
Dm = d - 0.5 ( 2) = 19mm
Tan ∝ = [tex]\frac{L}{\pi Dm}[/tex] where L = 2*2 = 4
hence ∝ = 3.83⁰
given f = 0.1 , Tan Ф = 0.1. hence Ф = 5.71⁰
insert all the values into equation 1
T = 1.59 Nm
Determine the power needed using this equation
[tex]\frac{2\pi NT }{60}[/tex] = [tex]\frac{2\pi * 300 * 1.59}{60}[/tex]
= 49.95 watts
B) checking if the self-locking condition of the power screw is satisfied
Ф > ∝ hence it is self locking condition is satisfied
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!!!
Many HVACR industry publications are published by
Answer:
HVACR Industry Trade Groups
Explanation:
How old are you? answer this question plz lol I will mark someone as brainliest
Answer:
100000000000000000000000
Two mass streams of the same ideal gas are mixed in a steady-flow chamber while receiving energy by heat transfer from the surroundings. The mixing process takes place at constant pressure with no work and negligible changes in kinetic and potential energies. Assume the gas has constant specific heats.
a. Determine the expression for the final temperature of the mixture in terms of the rate of heat transfer to the mixing chamber and the inlet and exit mass flow rates.
b. Obtain an expression for the volume flow rate at the exit of the mixing chamber in terms of the volume flow rates of the two inlet streams and the rate of heat transfer to the mixing chamber.
c. For the special case of adiabatic mixing, show that the exit volume flow rate is the sum of the two inlet volume flow rates.
Answer:
(a)The final temperature of mixture is T₃ =m₁T₁/m₃+ m₂T₂/m₃ + Qin/m₃Cp
(b) The final volume is V₃ =V₁ + V₂ + RQin/P₃Cp
(c) The volume flow rate at exit is V₃ =V₁ + V₂
Explanation:
Solution
Now
The system comprises of two inlets and on exit.
Mass flow rate enthalpy of fluid from inlet -1 be m₁ and h₁
Mass flow rate enthalpy of fluid from inlet -2 be m₂ and h₂
Mass flow rate enthalpy of fluid from exit be m₃ and h₃
Mixing chambers do not include any kind of work (w = 0)
So, both the kinetic and potential energies of the fluid streams are usually negligible (ke =0, pe =0)
(a) Applying the mass balance of mixing chamber, min = mout
Applying the energy balance of mixing chamber,
Ein = Eout
min hin =mout hout
miCpT₁ + m₂CpT₂ +Qin =m₃CpT₃
T₃ = miCpT₁/m₃CpT₃ + m₂CpT₂/m₃CpT₃ + Qin/m₃CpT₃ +
T₃ =m₁T₁/m₃+ m₂T/m₃ + Qin/m₃Cp
The final temperature of mixture is T₃ =m₁T₁/m₃+ m₂T₂/m₃ + Qin/m₃Cp
(b) From the ideal gas equation,
v =RT/PT
v₃ = RT₃/P₃
The volume flow rate at the exit, V₃ =m₃v₃
V₃ = m₃ RT₃/P₃
Substituting the value of T₃, we have
V₃=m₃ R/P₃ (=m₁T₁/m₃+ m₂T₂/m₃ + Qin/m₃Cp)
V₃ = R/P₃ (m₁T₁+ m₂T₂ + Qin/Cp)
Now
The mixing process occurs at constant pressure P₃=P₂=P₁.
Hence V₃ becomes:
V₃=m₁RT₁/P₁ +m₂RT₂/P₂ + RQin/P₃Cp
V₃ =V₁ + V₂ + RQin/P₃Cp
Therefore, the final volume is V₃ =V₁ + V₂ + RQin/P₃Cp
(c) Now for an adiabatic mixing, Qin =0
Hence V₃ becomes:
V₃ =V₁ + V₂ + r * 0/P₃Cp
V₃ =V₁ + V₂ + 0
V₃ =V₁ + V₂
Therefore the volume flow rate at exit is V₃ =V₁ + V₂
A 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 plant of order 50 is to track steps and sinusoids of frequency ω = 1 rad/sec. Write down the form of the pole placement controller which will guarantee stability and tracking. g
Answer:
The term for the pole placement controller is G/(s² + 1) +GH
Explanation:
Solution
Given that:
A plant of order = 50
The sinusoids of frequency ω = 1 rad/sec.
Lt the transfer of equation of plant be represented as follows:
T/F = G/1+GH
= K/ans^50 + ans - 1^49 +........As +a₀
The pole placement order becomes:
Step 1:
Gc (s) =A/s
Now
The transfer function = GGc/1 +GG c H
=G/s + GHA
Step 2:
For sinusoidal controller w = = 1 rad/sec.
Gc (s) = w/s² + w²
= 1 + /s² + 1
Thus
The transfer function = GGc/1 +GGcH
= G/(s² + 1) +GH
the term for the pole placement controller is G/(s² + 1) +GH
The liquid-phase reaction A + B → C follows an elementary rate law and is carried out isothermally in a flow system. The concentrations of A and B feed streams are 2 M before mixing. The volumetric flow rate of each stream is 5 dm3 /min and the entering temperature is 300 K. The streams are mixed immediately before entering. Two reactors are available: One is a gray 200.0 dm3 CSTR that can be heated to 77°C or cooled to 0°C, and the other is a white 800.0 dm3 PFR operated at 300 K that cannot be heated or cooled but can be painted red or black. (Note: k = 0.07 dm3 /mol*min at 300 K and E = 20 kcal/mol.) How long would it take to achieve 90% conversion in a 200 dm3 batch reactor with CA ° = CB ° = 1 ???? after mixing at a temperature of 70°C?
Answer:
1.887 minutes
Explanation:
We are given k = 0.07 dm3 /mol*min at 300 K and E = 20 kcal/mol = 20000 cal/mol
To solve this, first of all let's calculate the rate constant(k);
For this question, The formula is;
K(t) = k(300K) × exp[(E/R)((1/300) - (1/T2))]
R is gas constant = 1.987 cal/mol.K
For temperature of 70°C which is = 70 + 273K = 343K, we have;
K(343) = 0.07 × exp[(20000/1.987)((1/300) - (1/343))]
K(343) = 4.7 dm³/mol.min
The design equation is;
dX/dt = -(rA/C_Ao) = K•(C_Ao)²•(1 - X)²/(C_Ao) = (KC_Ao)(1 - X)²
Since there is no change in volume by cause of the state at which the reaction is carried out, that is liquid. Thus, integrating and solving for time for a 90% conversion we obtain;
(0.9,0)∫dX/(1 - X)².dX = (KC_Ao)((t, 0)∫dt
So, we'll get;
0.9/(1 - 0.9) = 4.77 × 1 × t
t = 9/4.77
t = 1.887 minutes
The output S/N at thereceiver must be greater than 40 dB. The audio signal has zero mean, maximum amplitude of 1, power of ½ Wand bandwidth of 15 kHz. The power spectral density of white noise N0/2 = 10-10W/Hz and the power loss in the channel is 50 dB. Determine the transmit power required and the bandwidth needed.
Given that,
The output signal at the receiver must be greater than 40 dB.
Maximum amplitude = 1
Bandwidth = 15 kHz
The power spectral density of white noise is
[tex]\dfrac{N}{2}=10^{-10}\ W/Hz[/tex]
Power loss in channel= 50 dB
Suppose, Using DSB modulation
We need to calculate the power required
Using formula of power
[tex]P_{L}_{dB}=10\log(P_{L})[/tex]
Put the value into the formula
[tex]50=10\log(P_{L})[/tex]
[tex]P_{L}=10^{5}\ W[/tex]
For DSB modulation,
Figure of merit = 1
We need to calculate the input signal
Using formula of FOM
[tex]FOM=\dfrac{\dfrac{S_{o}}{N_{o}}}{\dfrac{S_{i}}{N_{i}}}[/tex]
[tex]1=\dfrac{\dfrac{S_{o}}{N_{o}}}{\dfrac{S_{i}}{N_{i}}}[/tex]
[tex]\dfrac{S_{i}}{N_{i}W}=\dfrac{S_{o}}{N_{o}}[/tex]
Put the value into the formula
[tex]\dfrac{S_{i}}{2\times10^{-10}\times15\times10^{3}}<40\ dB[/tex]
[tex]\dfrac{S_{i}}{30\times10^{-7}}<10^{4}[/tex]
[tex]S_{i}<30\times10^{-3}[/tex]
[tex]S_{i}=30\times10^{-3}[/tex]
We need to calculate the transmit power
Using formula of power transmit
[tex]S_{i}=\dfrac{P_{t}}{P_{L}}[/tex]
[tex]P_{t}=S_{i}\times P_{L}[/tex]
Put the value into the formula
[tex]P_{t}=30\times10^{-3}\times10^{5}[/tex]
[tex]P_{t}=3\ kW[/tex]
We need to calculate the needed bandwidth
Using formula of bandwidth for DSB modulation
[tex]bandwidth=2W[/tex]
Put the value into the formula
[tex]bandwidth =2\times15[/tex]
[tex]bandwidth = 30\ kHz[/tex]
Hence, The transmit power is 3 kW.
The needed bandwidth is 30 kHz.