A pump of a water distribution system at 25°C is powered by a 15 kW electric motor whose efficiency is 90 percent. The water flow rate through the pump is 50 L/s. The diameters of the inlet and outlet pipes are both 5 cm and the elevation difference across the pump is negligible. If the absolute pressures at the inlet and outlet of the pump are measured as 100 kPa and 300 kPa, respectively, determine the friction loss in the system.
Answers
The friction loss in the system is 3.480 kilowatts.
Procedure - Friction loss through a pumpPump modelLet suppose that the pump within a distribution system is an open system at steady state, whose mass and energy balances are shown below:
Mass balance\(\dot m_{in}-\dot m_{out} = 0\) (1)
\(\dot m_{in} = \frac{\dot V_{in}}{\nu_{in}}\) (2)
\(\dot m_{out} = \frac{\dot V_{out}}{\nu_{out}}\) (3)
Energy balance
\(\eta \cdot \dot W_{el} + \dot m_{in}\cdot (h_{in}-h_{out}) - \dot W_{f} = 0\) (4)
Where:
\(\dot m_{in}\) - Inlet mass flow, in kilograms per second.\(\dot m_{out}\) - Outlet mass flow, in kilograms per second. \(\dot V_{in}\) - Inlet volume flow, in cubic meters per second. \(\dot V_{out}\) - Outlet volume flow, in cubic meters per second. \(\nu_{in}\) - Inlet specific volume, in cubic meters per kilogram.\(\nu_{out}\) - Outlet specific volume, in cubic meters per kilogram.\(\eta\) - Pump efficiency, no unit.\(\dot W_{el}\) - Electric motor power, in kilowatts.\(h_{in}\) - Inlet specific enthalpy, in kilojoules per kilogram.\(h_{out}\) - Outlet specific enthalpy, in kilojoules per kilogram. \(\dot W\) - Work losses due to friction, in kilowatts. Data from steam tablesFrom steam tables we get the following water properties at inlet and outlet:
Inlet
\(p = 100\,kPa\), \(T = 25\,^{\circ}C\), \(\nu = 0.001003\,\frac{kJ}{kg}\), \(h = 104.927\,\frac{kJ}{kg}\), Subcooled liquid
Outlet
\(p = 300\,kPa\), \(T = 25\,^{\circ}C\), \(\nu = 0.001003\,\frac{kJ}{kg}\), \(h = 105.128\,\frac{kJ}{kg}\), Subcooled liquid
Calculation of the friction loss in the systemIf we know that \(\dot V_{in} = 0.05\,\frac{m^{3}}{s}\), \(\nu_{in} = 0.001003\,\frac{m^{3}}{kg}\), \(h_{in} = 104.927\,\frac{kJ}{kg}\), \(h_{out} = 105.128\,\frac{kJ}{kg}\), \(\eta = 0.90\) and \(\dot W_{el} = 15\,kW\), then the friction loss in the system is:
\(\dot W_{f} = \frac{\dot V_{in}}{\nu_{in}}\cdot (h_{in} - h_{out}) + \eta \cdot \dot W_{el}\)
\(\dot W_{f} = \left(\frac{0.05\,\frac{m^{3}}{s} }{0.001003\,\frac{m^{3}}{kg} } \right)\cdot \left(104.927\,\frac{kJ}{kg}-105.128\,\frac{kJ}{kg}\right) + (0.90)\cdot (15\,kW)\)
\(\dot W_{f} = 3.480\,kW\)
The friction loss in the system is 3.480 kilowatts. \(\blacksquare\)
To learn more on pumps, we kindly invite to check this verified question: https://brainly.com/question/544887
Related Questions
Identify the careers that match the descriptions. Operates machines that cut through rocks underground so natural resources can be harvested: Studies and manages natural resources to protect the environment: Manages forests for conservation, human enjoyment, and harvesting: Inspects, measures, and classifies logs based on quality: Operates machinery to cut down trees and move logs:
Answers
Answer:
1. Operates machines that cut through rocks underground so natural resources can be harvested: Mine-cutting and channeling operator
2. Studies and manages natural resources to protect the environment: Conservation Scientist
3. Manages forests for conservation, human enjoyment, and harvesting: Forster
4. Inspects, measures, and classifies logs based on quality: Log grader or scaler
5. Operates machinery to cut down trees and move logs: Logging equipment Operator
Explanation:
Conservation Scientist – studies and manages natural resources to protect the environment and support human uses of natural resources
Forester – manages forests for conservation, human enjoyment, and tree harvesting
Mine Cutting and Channeling Machine Operator – operates machinery in underground mines that bring natural resources up to the surface for human use
Logging Equipment Operator – operates logging machinery, such as tractors or bulldozers
Log Grader or Scaler – inspects, measures, and classifies logs based on their quality
The careers that match the given descriptions are; Conservation Scientist, Forester , Mine Cutting and Channeling Machine Operator ,and Logging Equipment Operator.
What are the careers that match the given descriptions?Conservation Scientist deals with the studies and manages natural resources to protect the environment and support human uses of natural resources
Forester deals with forests for conservation, human enjoyment, and tree harvesting
Mine Cutting and Channeling Machine Operator are the operates machinery in underground mines that bring natural resources up to the surface for human use
Logging Equipment Operator are the operates logging machinery, such as tractors or bulldozers
Log Grader or Scaler deals with the inspects, measures, and classifies logs based on their quality.
The careers that match the given descriptions are; Conservation Scientist, Forester , Mine Cutting and Channeling Machine Operator ,and Logging Equipment Operator.
Learn more about the concept here;
https://brainly.com/question/1615416
#SPJ2
_____is the ability of a system to grow as the volume of users increases.
For others taking this class that have not found the answer
Answers
Answer:
Scalability
Explanation:
just took a test and it was right.
A system samples a sinusoid of frequency 230 Hz at a rate of 175 Hz and writes the sampled signal to its output without further modification. Determine the frequency that the sampling system will generate in its output.
a. 120
b. 55
c. 175
d. 230
Answers
In which situation is a are food service workers not required to wash their hands?
Answers
Answer:
when wearing gloves?
Explanation:
?
or when off duty
Answer:
When off duty
Explanation:
Hey any one ride dirtbikes here
Answers
Answer:
Yes all the time
Explanation:
899.99 Is to much right
Answers
Answer:
no not for all that in the set
Explanation:
pic also looks fake so i wouldnt trust it.
A material's resistance to repetitive or alternating stressing without failure is refereed to as?
Answers
The material's resistance to repetitive or alternating stressing without failure is referred to as fatigue strength.
Fatigue strength is a crucial characteristic of materials that undergo cyclic loading or repeated stress over time. When a material is subjected to repetitive or alternating stresses, it can experience microstructural changes that can lead to failure, even when the applied stress is below its ultimate strength.
Fatigue failure often occurs after a large number of stress cycles, and it is typically characterized by cracks initiating and propagating through the material.
Materials with high fatigue strength can withstand a significant number of stress cycles without failure. They exhibit a greater ability to resist crack initiation and propagation, which is essential for applications involving cyclic loading, such as in structural components, machinery, and vehicles.
Several factors influence a material's fatigue strength. These include its inherent properties, such as composition, microstructure, and heat treatment. Surface conditions, environmental factors (such as temperature and humidity), and loading parameters (such as stress amplitude and frequency) also play crucial roles in determining fatigue resistance.
Understanding and considering the fatigue strength of materials is vital for ensuring the reliability and longevity of structures and components that experience cyclic loading. Engineers and designers must evaluate the fatigue characteristics of materials through various tests and simulations to ensure their suitability for specific applications and to prevent unexpected failures.
Learn more about Resistance
brainly.com/question/33728800
#SPJ11
4. On wet roads, the chance of hydroplaning increases with the increase of speed.
True
False
Answers
Answer:
The answer to the question is True
On wet roads, the chance of hydroplaning increases with the increase of speed. Thus, the given statement is true.
During rainy weather, roads may become slippery and difficult to drive on. Slippery roads may also arise as a result of snow or ice. The fact that the road surface has less traction than normal is what makes it slippery. On slippery roads, it is recommended that drivers slow down to reduce the risk of skidding, sliding, or losing control of their cars, especially when taking turns.
Drivers should also increase their following distance and avoid abrupt braking or accelerating. Drivers should not drive faster than 25 mph on slippery roads, and they should not increase their speed to avoid hydroplaning. Instead, drivers should slow down.
Learn more about slippery roads:
brainly.com/question/1213174
#SPJ4
Hey guys can anyone list chemical engineering advancement that has been discovered within the past 20 years
Answers
Nanopesticides. The world population keeps growing. ...
Enantio selective organocatalysis. ...
Solid-state batteries. ...
Flow Chemistry. ...
Porous material for Water Harvesting. ...
Directed evolution of selective enzymes. ...
From plastics to monomers. ...
An oil pump operating at steady state delivers oil at a rate of 10 lb/s through a 1-in.-diameter exit pipe. The oil, which can be modeled as incompressible, has a density of 55 lb/ft^3 and experiences a pressure rise from inlet to exit of 40 lb-/in^2. There is no significant elevation difference between inlet and exit, and the inlet kinetic energy is negligible. Heat transfer between the pump and its surroundings is negligible, and there is no significant change in temperature as the oil passes through the pump.
Determine the velocity of the oil at the exit of the pump, in ft/s, and the power required for the pump, in hp.
Answers
Answer:
30 lbs
Explanation:
Answer:
The answer above is correct. 30lbs
Explanation:
Where does Burj Khalifa located? and how many meters?
Answers
Answer:
Burj Khalifa is located in dubai UAE at over 828m
Explanation:
828 metres
Answer:
The Burji Khalifa, known as the Burj Dubai prior to its inauguration in 2010, is a skyscraper in Dubai, United Arab Emirates. With a total hight of 829.8 m and a roof hight of 828 m, the Burji Khalifa has been the tallest structure and building in the world since its topping out in 2009.
how does the 3d model you created compare with what you would expect based on your observations of the simulated mechanisms from the previous activity, including pulley rotation direction, number of rotations made by each of the two pulleys, and limitations of the cad model? pulley mechanism
Answers
The limitations of the CAD model need to be considered when comparing the two mechanisms. Pulley mechanism: A pulley mechanism is a type of mechanical device that uses a wheel with a groove along its edge to move a rope or cable.
The rope or cable is inserted into the groove, and the wheel is rotated. As the wheel rotates, it causes the rope or cable to move. This can be used to lift or move objects.To create a 3D model of a pulley mechanism, one must first understand how the mechanism works. This includes understanding the direction of rotation of the pulley and the number of rotations made by each of the two pulleys. The 3D model should accurately represent these characteristics of the mechanism.The limitations of the CAD model should also be taken into account when comparing the 3D model to the simulated mechanism from the previous activity.
Learn more about CAD model: https://brainly.com/question/18995936
#SPJ11
The three main principles in engineering design are:
Answers
The three main principles in engineering design are: strategic balance, top management approach and team work.
What does principles in engineering design means?The principles are fundamental concepts that engineers use to develop effective solutions to complex problems. These principles are based on scientific and mathematical principles as well as practical considerations related to the materials, technologies and resources available to the engineer.
The engineering design process involves several stages, including problem identification, research, concept development, prototyping and testing. Throughout each stage, engineers apply various principles to ensure that their designs meet the needs and requirements of the intended users.
Read more about engineering design
brainly.com/question/411733
#SPJ1
Demand - The company works on two shifts, each of eight hours, with a 30 minutes break for each shift. - The production family A is made by a range of 68 different products, from Al to A68 (products with low volume/high variety). - The total demand of the production family A is on average 450 pieces per day. Processes - There are three main production stages (machining, heat treatment, assembly, in this sequence). In each of these stages, there are one machine and one operator fully dedicated to this product family. Downstream of the assembly, the piece goes to a warehouse, ready for shipment. Before each stage there is a stock where pieces wait to be processed. - Cycle times and setups are very similar for each product. - Upstream of the machining stage there are stocks of raw material for a requirement of 10 days. Information flow - Customers make a forecast (to 30/60/90 days) and send it monthly to the Production Planning department (PP). - Customers send orders to Sales daily, with agreed shipping dates, generally equal to 15 days. The demand of the various products of the family is quite similar. - PP tracks in the system the orders received from Sales and develops a weekly production plan for each production process and a daily scheduling plan for deliveries to Shipment. Company is indeed working with daily shipments. - PP sends a forecast ( 30/60 days) to the supplier and confirms orders weekly. The supplier delivers weekly. Q1: Create a Value Stream Map for the current state (Provide all necessary data in VSM as learned in the class) and calculate the following: i) Lead Time ii) Value Added Time iii) Process Cycle Efficiency Q2: Based on the gap between customer demand and actual daily throughput: a) Use 5 W1H, Cause and Effect Diagram and 5 why analysis to identify the root cause of throughput loss. (Start with the problem statement as: "Missing customer demand due to throughput loss"). b) Once Lean tool applied to identify the loss, provide recommendation to make overall improvement and draw future State VSM
Answers
The production family A is made by a range of 68 different products, from Al .on two shifts, each of eight hours, with a 30 minutes break for each shift.
What is demand?Demand is an economic concept that relates to a consumer's desire to purchase goods and services and willingness to pay a specific price for them. An increase in the price of a good or service tends to decrease the quantity demanded. Likewise, a decrease in the price of a good or service will increase the quantity demanded.Demand is a concept that consumers and businesses are very familiar with because it makes sense and occurs naturally in the course of practically any day. For example, shoppers with an eye on products that they want will buy more when the products' prices are low. When something happens to raise the prices, such as a change of season, shoppers buy fewer or perhaps none at all.To learn more about demand refer to:
https://brainly.com/question/1222851
#SPJ1
Question 27
Which lines demonstrate autoboxing ?
1 Integer intValue = 20;
2 double myScore = 30.0;
3 Double yourScore = myScore;
4 Character yourGrade = 'A';
5 char myGrade = yourGrade;
Group of answer choices
a. 1, 3, 4
b. 2, 5
c. 3, 5
d. 1, 2, 3, 4, 5
Answers
The lines demonstrate autoboxing is1 Integer intValue = 20; 3 Double = myScore; 4 Character = 'A'. The correct option is a.
What is autoboxing?Autoboxing is the automatic conversion that the Java compiler makes between the primitive types and their corresponding object wrapper classes. For example, converting an int to an Integer, a double to a Double, and so on. If the conversion goes the other way, this is called unboxing. Autoboxing and unboxing let developers write cleaner code, making it easier to read.
The technique lets us use primitive types and Wrapper class objects interchangeably and we do not need to perform any type casting explicitly.
Learn more about autoboxing, here:
https://brainly.com/question/29223108
#SPJ1
Loading that acts perpendicular to the longitudinal axis is called?
Answers
Question Completion Status:
The point of application of the total pressure on surface is
O a. None of the above
O b. Centroid of the surface
O c. Centre of pressure
Answers
Answer: c. Centre of pressure
Explanation:
Pressure is applied on a surface when a force is exerted on a particular point on that surface by another object when the two come into contact with each other.
The point where the pressure is applied is known as the centre of the pressure with the force then spreading out from this point much like an epicentre in an earthquake.
Draw a radial power circuit arrangement containing 3 single fused sockets and 2 double unfused sockets showing the live, earth and neutral wiring
Answers
Answer:
Attached below is the Radial power circuit arrangement
Explanation:
Radial power circuit arrangement is done in a way that a single cable starts from the fuse box and connects to all the outlet socket contained in the circuit also the cable contains wires ( live , neutral and earth )
The advantage of a radial power circuit arrangement is that it enables easy identification of electrical faults on the circuit.
INSTRUCTIONS
Create a "starter" risk register for the two projects (A and B) described below. Include at least 6 risks for project A
Project A
Description
Building a garden shed. This includes the design of the shed, sourcing all the materials required for construction, and putting all of the various pieces together to get the finished shed.
Outcome
A finished garden shed.
Proposed Tasks
There are going to be certain tasks that depend on others. You’re going to need to:
Get a set of blueprints for the shed and clear and prepare the area for construction
Source all of the materials for the construction
Prepare the foundation and start constructing the beams of the floor
Lay the floorboards
Construct the frames of the walls and raise and fit each of them
Frame the roof and attach the roofing
Fit in all the siding for the walls
Fit in the windows and the doors
From this, it’s obvious that you won’t be able to start fitting the walls until the floor is in place or start work on the roof until walls have been raised.
Stakeholders
Besides yourself and those living in your home, your team can be neighbors, or friends. You’ll need to lead them and give them direction on the tasks you want them to do. Outside risks include bad weather or the hardware store not having certain items or being closed when you need it.
Timeline
For a project like this that is relatively simple, the timeline depends on how large your team is. With 10 people working on a garden shed, it could be finished in a matter of hours, but doing it alone may take 2-3 weekends of time.
Answers
A risk register is a log of all potential hazards, risks, and uncertainties that a project may encounter. It also has an explanation of the probability of the danger occurring and its potential impact.
A risk register's purpose is to assist in the identification, assessment, and management of risks associated with a project and is an essential part of a successful risk management strategy. As such, the risk register has six components, including the risk description, risk cause, impact, risk likelihood, risk impact, and risk ranking.The following are six potential hazards for Project A and their explanations:
1. Weather Issues: Bad weather can slow down the construction process, make it dangerous to work outside, or damage materials.
2. Availability of Materials: If materials are scarce, it can delay or halt the construction project.
3. Time Constraints: Limited time can result in project delays or cutting corners, which can impact the quality of work.
4. Cost Overruns: Unexpected or uncontrollable costs can result in the project being halted or completed poorly.
5. Inadequate or Faulty Tools: This can affect work quality, safety, and efficiency, ultimately impacting the project schedule and costs.
6. Safety Issues: Inadequate safety protocols can result in accidents that could lead to injury or death of workers on the site.In conclusion, the risk register for Project A should outline potential hazards, their causes, impact, likelihood, and ranking, as well as mitigation strategies. The risk register should be reviewed and updated regularly to ensure that new risks are identified and addressed.
To know more about risk register visit:
https://brainly.com/question/31663618
#SPJ11
A gas weighs 16 N/m^3 at 25 C and at an absolute pressure of 0.25 N/mm^2. Determine the gas constant and density of the gas.(hint: use gas law PV =mRT)
Answers
The gas constant (R) is approximately 514.4 Nm/kg-K and the density (ρ) of the gas is approximately 1.63 kg/m³.
The ideal gas law equation is PV = mRT
Where:
P = Pressure
V = Volume
m = Mass (or amount of substance)
R = Gas Constant
T = Temperature
Given information:
Pressure (P) = 0.25 N/mm² = 0.25 × 10⁶ N/m²
Volume (V) = 1 m³ (since we are given the gas weight per cubic meter)
Temperature (T) = 25 °C
= 25 + 273.15 K (convert Celsius to Kelvin)
Let's solve for the gas constant (R) using the given values and rearranging the ideal gas law equation:
R = PV / (mT)
Now, we need to calculate the mass (m) of the gas using the given gas weight:
Weight (W) = 16 N/m³
Weight (W) = m × g
Where g = acceleration due to gravity
= 9.81 m/s²
m = W / g
m = 16 N/m³ / 9.81 m/s²
Now, we can calculate the gas constant (R):
R = (PV)/(mT)
Substitute the given values:
R = (0.25 × 10⁶ N/m² × 1 m³) / (1.63 × (298.15)
R=250000/485.98
R=514.4 Nm/kg-K
To find the density (ρ) of the gas, we can rearrange the ideal gas law equation:
ρ = m / V
Substitute the calculated mass (m) and volume (V):
ρ = (16 N/m³ / 9.81 m/s²) / 1 m³
Calculate ρ:
ρ = 1.63 kg/m³
Hence, the gas constant (R) is approximately 514.4 Nm/kg-K and the density (ρ) of the gas is approximately 1.63 kg/m³.
To learn more on ideal gas law click here:
https://brainly.com/question/30458409
#SPJ3
I want to draw a monster should i do it on my free time and if you want to give me ideas.
Answers
Answer:
yes
Explanation:
an idea could be a jack o lantern monster since it Halloween tomorrow
Which of the following is NOT a risky food:
a
Raw Meat
b
Uncleaned fruits & vegetables
c
Bread
d
All of the above
e
Soft Cheeses
Answers
i think it's c. bread.
Answer:I think raw meat because if you eat raw meat you get sick and get stomach aches so always when you cook meat it kill the bacteria
Explanation:what I'm trying to says is stay safe
Give me source code of Simple openGL project. ( without 3D or Animation) simple just.
Answers
Answer:
Use GitHub or stackoverflow for this answer
Explanation:
It helps with programming a lot
A cube of edge 4 inches is cut by a plane containing 2 diagonally opposite edges
of the cube find the area of the section formed.
Answers
Answer:
So its area A = 4 * 4sqrt(2) = 16sqrt(2) inches^2
Explanation:
In order to find the area of the section, we need to find the length of one of the diagonals.
Using the Pythagorean Theorem, a^2 + b^2 = c^2, we pick any side of the cube which in
itself is a square with sides 4 inches each. The length of the diagonal of the square is
2(4^2) = c^2 or c = 4sqrt(2).
To calculate the area of the section, we must first determine the length of one of the diagonals. Using the Pythagorean Theorem, \(\bold{a^2 + b^2 = c^2}\), one selects any side of the cube which in its a square with four-inch sides.
The diagonal of a square has a length:\(\to 2(4^2) = c^2 \\\\ \to c = 4\sqrt{(2)}\)
A section is now a rectangle with sides 4 and \(4\sqrt{(2)}\). So its area\(\to A = 4 \times 4\sqrt{(2)} = 16\sqrt{(2)}\ inches^2\)
Therefore, the answer is "\(\bold{ 16\sqrt{(2)}\ inches^2}\)".
Learn more:
brainly.com/question/44587
FILL IN THE BLANK._______ is a command-line function for viewing and setting wireless interface parameters and is common to nearly all version of Linux and UNIX.
Answers
"iwconfig" is used to configure wireless network interface parameters such as SSID, encryption key, and power management features, among other things.
This command is a part of the wireless-tools package and is normally available on most Linux distributions.To run the "iwconfig" command, you must first open a terminal window. The command is executed by typing "iwconfig" followed by the name of the wireless network interface you wish to manage. The basic syntax for running the "iwconfig" command is as follows: iwconfig [interface] [options]The [interface] parameter is the name of the wireless network interface that you want to configure. You can obtain a list of available wireless network interfaces by using the "ifconfig" command. If the [interface] parameter is omitted, "iwconfig" will show the parameters for all of the available wireless interfaces on your system. Once you have specified the [interface] parameter, you can specify any number of [options] to configure the wireless interface.The "iwconfig" command is a valuable tool for managing wireless networks on Linux and UNIX systems.By using this command, you can configure your wireless interface to operate more efficiently, as well as troubleshoot any problems that you may encounter while using your wireless network.for more such question on parameter
https://brainly.com/question/29673432
#SPJ11
what is ph of the solution if 1.45 l of 0.056 m hno3 and 0.52 l of 0.13
Answers
The pH of the solution would be approximately 2.14.
To determine the pH of a solution, we need to know the concentration of the acidic or basic species present. In this case, we have two solutions: one containing 1.45 L of 0.056 M HNO3 (nitric acid) and the other containing 0.52 L of 0.13 M (sodium hydroxide) NaOH.
Let's calculate the number of moles of HNO3 and NaOH in their respective solutions:
Moles of HNO3 = volume (L) × concentration (M)
= 1.45 L × 0.056 M
= 0.0812 moles of HNO3
Moles of NaOH = volume (L) × concentration (M)
= 0.52 L × 0.13 M
= 0.0676 moles of NaOH
Since HNO3 is a strong acid and NaOH is a strong base, they will react in a 1:1 stoichiometric ratio. This means that for every mole of HNO3, one mole of NaOH will react.
To determine the excess reactant, we compare the number of moles of HNO3 and NaOH:
Excess moles of HNO3 = Moles of HNO3 - Moles of NaOH
= 0.0812 moles - 0.0676 moles
= 0.0136 moles of HNO3
Since HNO3 is an acid, the excess HNO3 will contribute to the overall acidity of the solution. The pH of an acidic solution is determined by the concentration of H+ ions, which can be calculated using the equation:
pH = -log[H+]
To find the concentration of H+ ions, we need to convert the excess moles of HNO3 to concentration by dividing it by the total volume of the solution (1.45 L + 0.52 L):
[H+] = moles of HNO3 / total volume (L)
= 0.0136 moles / (1.45 L + 0.52 L)
= 0.00716 M
Finally, we can calculate the pH:
pH = -log[H+]
= -log(0.00716)
≈ 2.14
Thus, the answer is 2.14.
Learn more about pH:
https://brainly.com/question/12609985
#SPJ11
Determine the resistance of 3km of copper having a diameter of 0,65mm if the resistivity of copper is 1,7x10^8
Answers
Answer:
Resistance of copper = 1.54 * 10^18 Ohms
Explanation:
Given the following data;
Length of copper, L = 3 kilometers to meters = 3 * 1000 = 3000 m
Resistivity, P = 1.7 * 10^8 Ωm
Diameter = 0.65 millimeters to meters = 0.65/1000 = 0.00065 m
\( Radius, r = \frac {diameter}{2} \)
\( Radius = \frac {0.00065}{2} \)
Radius = 0.000325 m
To find the resistance;
Mathematically, resistance is given by the formula;
\( Resistance = P \frac {L}{A} \)
Where;
P is the resistivity of the material. L is the length of the material.A is the cross-sectional area of the material.First of all, we would find the cross-sectional area of copper.
Area of circle = πr²
Substituting into the equation, we have;
Area = 3.142 * (0.000325)²
Area = 3.142 * 1.05625 × 10^-7
Area = 3.32 × 10^-7 m²
Now, to find the resistance of copper;
\( Resistance = 1.7 * 10^{8} \frac {3000}{3.32 * 10^{-7}} \)
\( Resistance = 1.7 * 10^{8} * 903614.46 \)
Resistance = 1.54 * 10^18 Ohms
1. Consider three dielectric media with flat and parallel boundaries with refractive indices n1, n2, and n3. Show that for normal incidence the reflection coefficient between layers 1 and 2 is the same as that between layers 2 and 3 if n2 = √[n1n3]. What is the significance of this?
2. Consider a Si photodiode that is designed for operation at 900 nm. Given a choice of two possible antireflection coatings, SiO2 with a refractive index of 1.5 and TiO2 with a refractive index of 2.3 which would you use and what would be the thickness of the antireflection coating? The refractive index of Si is 3.5. Explain your decision.
Answers
Answer:
1) r12 = r23 ( This signifies that the waves interfere destructively )
2) SiO2 should be chosen , Thickness = 150 nm
Explanation:
1 ) Prove that; r12 = r23
i) Considering light travelling in medium 1 ( i.e. incident between layers 1 and 2 )
r₁₂ ( reflection coefficient ) = ( n₁ - n₂ ) / ( n₁ + n₂ )
= ( n₁ - √n₁ n₃ ) / ( n₁ + √n₁ n₃ )
= \(\frac{1- \sqrt{\frac{n3}{n1} } }{1+ \sqrt{\frac{n3}{n1} } }\)
ii) considering light travelling in medium 2 ( i.e. incident between layers 2 and 3 )
r₂₃ ( reflection coefficient ) = ( n₂ - n₃ ) / (n₂ + n₃ )
= ( √n₁ n₃ - n₃ ) / ( √n₁ n₃ + n₃ )
= \(\frac{1- \sqrt{\frac{n3}{n1} } }{1+ \sqrt{\frac{n3}{n1} } }\)
hence r12 = r23 ( This signifies that the waves interfere destructively )
2) Determine the antireflection coating to use and the thickness
Refractive index of SiO2 = 1.5
Refractive index of TiO2 = 2.3
an ideal refractive index for an antireflection coating ( n2 )
= √n₁ n₃ = √(1)(3.5) = 1.87
the refractive index closest to this value = 1.5 ( hence SiO2 will be chosen )
Thickness of SiO2 ( diameter )
= 900 / ( 4*n2 )
= 900 / ( 4 * 1.5 ) = 900 / 6 = 150 nm
Consider a 1.5-m-high and 2.4-m-wide double-pane window consisting of two 3-mm-thick layers of glass (k = 0.78 W/m⋅K) separated by a 12-mm-wide stagnant airspace (k = 0.026 W/m⋅K). Determine the steady rate of heat transfer through this double-pane window and the temperature of its inner surface for a day during which the room is maintained at 20°C while the temperature of the outdoors is −5°C. Take the convection heat transfer coefficients on the inner and outer surfaces of the window to be h1 = 10 W/m2⋅K and h2 = 25 W/m2⋅K, respectively, and disregard any heat transfer by radiation.
Answers
Answer:
The answer is below
Explanation:
Given:
kg (glass) = 0.78 W/m⋅K, ka (air) = 0.026 W/m⋅K, h1 = 10 W/m2⋅K, h2 = 25 W/m2⋅K, glass length = Lg = 3 mm = 0.003 m, Lo = 3 mm = 0.003 m, La = 12 mm = 0.012 Height = 1.5 m, width = 2.4 m, room temperature = T = 20°C. Therefore:
Total resistance per unit area is given as:
\(R"=\frac{1}{h_1}+\frac{L_g}{k_g}+\frac{L_a}{k_a} +\frac{L_o}{k_g}+\frac{1}{h_2} \\\\R"=\frac{1}{10}+\frac{0.003}{0.78}+\frac{0.012}{0.026} +\frac{0.003}{0.78}+\frac{1}{25} \\\\R"=0.1+0.00385+0.46154+0.00385+0.04\\\\R"=0.60924\ K.m^2/W\)
Area = A = height * width = 1.5 m × 2.4 m = 3.6 m²
The change in temperature = ΔT = 20 °C - (-5 °C) = 25 °C
The rate of heat loss is given as:
\(\dot {Q}=A*\frac{\Delta T}{R"}= 3.6*\frac{25}{0.60924}\\ \\\dot {Q}=147.73\ W\)
The inner surface temperature (Ti) is given as:
\(T_i=T-\frac{\dot {Q}}{A} *\frac{1}{h_1}\\ \\T_i=20-\frac{147.73}{3.6}*\frac{1}{10}=15.9\ ^oC\)
You have just connected four new computer systems to an Ethernet switch using spare patch cablesZ after the installation, only three systems are able to access the network. You verify all client network settings and replace the network cars in the failed system. The client is still unable to access the network.
Which of the following might you suspect is the real cause of the problem.
Answers
The most likely cause of the problem after connecting four new computer systems to an Ethernet switch is might be a faulty Ethernet switch port.
Despite verifying the client network settings and replacing the network card in the failed system, the client is still unable to access the network. This suggests that the issue lies with the connection between the client system and the network. One possible cause is a faulty Ethernet switch port.
When connecting the four new computer systems to the Ethernet switch, it is possible that one of the spare patch cables was not properly connected or that the port on the Ethernet switch itself is malfunctioning. This would result in the client system not being able to establish a connection with the network.
Learn more about Ethernet https://brainly.com/question/31610521
#SPJ11