Answer:
T = 3460 K
Explanation:
See attachment for calculation.
Since the temperature we have is above the melting point of the metal, then we can conclude that it is too high for the diffusion process to be possible.
Should transistors used in switching circuits be biased in the active region? Why or why not?
Answer:
no
Explanation:
No. More power is dissipated when the transistor is in its active region. In general, transistors in switching circuits are biased either "on" or "off". Time spent in the active region is minimized.
_____
On the other hand, speed can be enhanced if the transistors are active. So, it's a speed/power trade-off. Usually power is of more interest, particularly when there are millions of switching circuits. However, in certain applications, speed may be the priority, so the transistor will be biased in its active region.
Facts about cellphones
Answer:
Your mobile phone has more computing power than the computers used for the Apollo 11 moon landing.
Mobile phones have to “work harder” to get a signal if you are in a moving vehicle.
The first mobile phone was made in 1973.
The first mobile phones that went on sale in 1983 cost nearly $4,000 each.
In 2012 Apple sold 340,000 phones per day.
4 out of 10 Brits admit to snooping on their partners phone.
Out of the 53% of snoopers that found incriminating evidence on their partner’s phone, 5% went on to terminate their relationship.
Waterproof mobile phones came to market because Japanese youngsters like to use them in the shower.
Apparently mobile phones have 18 times more bacteria on them than toilet handles!
Phubbing describes the act of snubbing someone by using your mobile phone in their company.
In 2015 more people died from taking selfies than shark attacks.
Teenagers that use a phone more than 2 hours a day increase their risk of depression and anxiety.
Nomobophobia is severe anxiety caused by the thought or act of losing your phone or running out of battery.
Explanation:
How natural gas works and operates?
PLEASE HELP!!!
A concrete batch plant has a batching chamber capacity of 12.5 cy and an average batching cycle time of 3 min. Plant efficiency is 84%. What is the estimated batching production in cy/hr?
Answer:
The estimated batching production is 210 cy/hr
Explanation:
Given;
capacity of the batching chamber of the plant, Q = 12.5 cy
average batching cycle time, t = 3 min
plant efficiency, n = 84 %
The estimated batching production is calculated as efficiency of the machine multiplied by the production rate in hour. This is given by the solution below;
Batching production = (nQ )/ t
[tex]Batching \ production = 0.84(\frac{12.5 \ cy}{3 \ min} *\frac{60 \ min}{1 \ hr})\\\\ Batching \ production = 210 \ cy/hr[/tex]
Therefore, the estimated batching production is 210 cy/hr
What is the meaning of *binuhat lakas nang loob na ibinaon
Answer:
carried courage buried
Explanation:
its Filipino
I need help on this ASAP PLZ?
Answer:
Explanation:
7. False
8. True
9. True
10.True
11. True
gasoline has a comparatively high btu per galloon rating around?
Answer:
116,090 Btus
Explanation:
The critical resolved shear stress for a metal is 36 MPa. Determine the maximum possible yield strength (in MPa) for a single crystal of this metal that is pulled in tension.
Answer:
72 MPa
Explanation:
Critical resolved shear stress = 36 MPa
calculate the maximum possible yield strength for a single crystal of the metal
first we have to express the critical resolved shear stress as
бy = 2т[tex]_{critical}[/tex]
given that the minimum stress needed to introduce yielding curve will occur at Ψ = λ = 45
where : бy = yielding stress
t[tex]_{critical}[/tex] = 36MPa
therefore the maximum possible yield strength
= (2) * (36)
= 72 MPa
Nicole designs the hardware configuration of workstations that will be deployed to a newly formed company. She sets up the networking capabilities and policies that will govern the workstations when connected to the company network. What is her role in her company?
Answer:
a Network Engineer (architect)
Explanation:
Indeed, as a Network Engineer, we would expect Nicole to be in charge of planning, setting up, and managing the software and hardware components of the computer networks so that they function as intended.
A Network Engineer therefore would be responsible for setting up the networking capabilities and policies that will govern the workstations when connected to the company network.
To determine if a product or substance being used is hazardous, consult:__________.
a. A dictionary
b. An MSDS
c. SAE standards
d. EPA guidelines
Answer:
Option B: An MSDS
Explanation:
A dictionary is used to check up the meaning of general words and not for checking if a substance being used is hazardous. Option A is wrong.
MSDS means "Material Safety Data Sheet" and it contains documents with information that relates to occupational health & safety for checking various substances and products. Thus, option B is correct.
SAE stands for Society of Automotive Engineering and their standards pertain to mainly Automobiles. Thus option C is wrong.
EPA guidelines are mainly for checking facility and environmental health and safety compliance. Thus, option D is wrong.
Estimate the rotor inertia assuming that the rotor is a cylinder of radius 8.98 mm, and length 25 mm, with a material of 100% copper. Explain why the rotor inertia may differ from these assumptions?
Answer:
The moment of inertia of the rotor is approximately [tex]1.105\times 10^{-6}[/tex] kilogram-square meters.
The rotor inertia may differ from these assumption due to differences in the shape of cross section.
Explanation:
We assume that rotor can be represented as a solid cylinder of radius [tex]r[/tex], length [tex]l[/tex], made of cooper ([tex]\rho = 8960\,\frac{kg}{m^{3}}[/tex]) and whose axis of rotation passes through its center of mass and is parallel to its cross section. By definition of Moment of Inertia and Theorem of Parallel Axes, the moment of inertia of the rotot is:
[tex]I = \frac{1}{4}\cdot \rho \cdot \left(\frac{\pi}{4} \right) \cdot R^{3}\cdot (3\cdot R^{2}+L^{2})[/tex]
[tex]I = \frac{\pi}{16}\cdot \rho \cdot R^{3}\cdot (3\cdot R^{2}+L^{2})[/tex] (Eq. 1)
Where:
[tex]\rho[/tex] - Density of copper, measured in kilograms per cubic meter.
[tex]R[/tex] - Radius of the rotor, measured in meters.
[tex]L[/tex] - Length of the rotor, measured in meters.
[tex]I[/tex] - Moment of inertia, measured in kilogram-square meters.
If we know that [tex]\rho = 8960\,\frac{kg}{m^{3}}[/tex], [tex]L = 25\times 10^{-3}\,m[/tex] and [tex]R = 8.98\times 10^{-3}\,m[/tex], the estimated moment of inertia of the rotor is:
[tex]I = \frac{\pi}{16}\cdot \left(8960\,\frac{kg}{m^{3}} \right)\cdot (8.98\times 10^{-3}\,m)^{3}\cdot [3\cdot (8.98\times 10^{-3}\,m)^{2}+(25\times 10^{-3}\,m)^{2}][/tex]
[tex]I \approx 1.105\times 10^{-6}\,kg\cdot m^{2}[/tex]
The moment of inertia of the rotor is approximately [tex]1.105\times 10^{-6}[/tex] kilogram-square meters.
From D'Alembert's Formula we know that net force of rigid bodies experimenting rotation equals the product of moment of inertia and angular acceleration. In this case, the purpose is minimizing moment of inertia and it is done by modifying the shape of the cross section so that rotor could be aerodynamically more efficient.
A 30-mm-diameter shaft, made of AISI 1018 HR steel, transmits 10 kW of power while rotating at 200 rev/min. Assume any bending moments present in the shaft to be negligibly small compared to the torque. Determine the static factor of safety based on:a) The maximum-shear-stress failure theory.b) The distortion-energy failure theory.
Answer:
a) According to the maximum-shear-stress failure theory, the static factor of safety of the shaft is 2.440.
b) According to the distortion-energy failure theory, the static factor of safety of the shaft is 2.816.
Explanation:
First, we need to determine the torque experimented by the shaft ([tex]T[/tex]), measured in kilonewton-meters, whose formula is described:
[tex]T = \frac{\dot W}{\omega}[/tex] (Eq. 1)
Where:
[tex]\dot W[/tex] - Power, measured in kilowatts.
[tex]\omega[/tex] - Angular velocity, measured in radians per second.
If we know that [tex]\dot W = 10\,kW[/tex] and [tex]\omega = 20.944\,\frac{rad}{s}[/tex], then the torque experimented by the shaft:
[tex]T = \frac{10\,kW}{20.944\,\frac{rad}{s} }[/tex]
[tex]T =0.478\,kN\cdot m[/tex]
Let consider that shaft has a circular form, such that shear stress is determined by the following formula:
[tex]\tau = \frac{16\cdot T}{\pi\cdot D^{3}}[/tex] (Eq. 2)
Where:
[tex]D[/tex] - Diameter of the shaft, measured in meters.
[tex]\tau[/tex] - Torsional shear stress, measured in kilopascals.
If we know that [tex]D = 0.03\,m[/tex] and [tex]T =0.478\,kN\cdot m[/tex], the torsional shear stress is:
[tex]\tau = \frac{16\cdot (0.478\,kN\cdot m)}{\pi\cdot (0.03\,m)^{3}}[/tex]
[tex]\tau \approx 90164.223\,kPa[/tex]
a) According to the maximum-shear-stress failure theory, we get that maximum shear stress limit is:
[tex]S_{ys} = 0.5\cdot S_{ut}[/tex] (Eq. 3)
Where:
[tex]S_{ys}[/tex] - Ultimate shear stress, measured in kilopascals.
[tex]S_{ut}[/tex] - Ultimate tensile stress, measured in kilopascals.
If we know that [tex]S_{ut} = 440\times 10^{3}\,kPa[/tex], the ultimate shear stress of the material is:
[tex]S_{ys} = 0.5\cdot (440\times 10^{3}\,kPa)[/tex]
[tex]S_{ys} = 220\times 10^{3}\,kPa[/tex]
Lastly, the static factor of safety of the shaft ([tex]n[/tex]), dimensionless, is:
[tex]n = \frac{S_{ys}}{\tau}[/tex] (Eq. 4)
If we know that [tex]S_{ys} = 220\times 10^{3}\,kPa[/tex] and [tex]\tau \approx 90164.223\,kPa[/tex], the static factor of safety of the shaft is:
[tex]n = \frac{220\times 10^{3}\,kPa}{90164.223\,kPa}[/tex]
[tex]n = 2.440[/tex]
According to the maximum-shear-stress failure theory, the static factor of safety of the shaft is 2.440.
b) According to the distortion-energy failure theory, we get that maximum shear stress limit is:
[tex]S_{ys} = 0.577\cdot S_{ut}[/tex] (Eq. 5)
If we know that [tex]S_{ut} = 440\times 10^{3}\,kPa[/tex], the ultimate shear stress of the material is:
[tex]S_{ys} = 0.577\cdot (440\times 10^{3}\,kPa)[/tex]
[tex]S_{ys} = 253.88\times 10^{3}\,kPa[/tex]
Lastly, the static factor of safety of the shaft is:
[tex]n = \frac{253.88\times 10^{3}\,kPa}{90164.223\,kPa}[/tex]
[tex]n = 2.816[/tex]
According to the distortion-energy failure theory, the static factor of safety of the shaft is 2.816.
Recently, due to rapid urbanization and mechanization residents of a city are suffering from harmful effects of the ultra violet rays. Depletion of which layer is likely to have led to this situation
(TCO 7) Find the resolution of the Fourier transform if a signal is sampled at 16,384 samples/second and we collect a total of 8,192 data points and then apply the FFT algorithm to them.
Answer:
Resolution of Fourier transform = 2Hz
Explanation:
Given:
Sample signals = 16,384 samples/second
Number of data points = 8,192 oints
Find:
Resolution of Fourier transform
Computation:
Resolution of Fourier transform = fs / N
Resolution of Fourier transform = 16,384 / 8,192
Resolution of Fourier transform = 2Hz
A car makes a hissing noise each time the A/C system and engine are turned off. Technician A says that the noise is caused by a refrigerant leak. Technician B says that the noise is caused by equalization of system pressures. Who is correct?
Answer:
It's equalization of the system
Explanation: If there was a leak it would likely leak all the time even if the car was turned off. Plus, a system leak bad enough to hear would drain the system of refrigerant very quickly and would no longer cool.
inspections may be_____ or limited to a specific area such as electrical or plumbing
A. Metering
B. General
Two vehicles collided head on while traveling on a curve tangent with a 3% grade. Vehicle V1 skidded 195 feet downhill before colliding with vehicle V2. Vehicle V2 skidded 130 feet. The police report estimates that the speed of both vehicles at impact was 25 mph, based on vehicle deformation. Assume a coefficient of friction of 0.48. What is V1 speed at the beginning of the skid?
Answer:
Speed V1 at the beginning of the skid = 57.075 mph
Explanation:
Calculate the V1 speed at the beginning of the skid
V1 ( speed before brake was applied ) = ?
distance travelled by Vehicle 1 = 195 ft
curve tangent for vehicle 1 = - 3% = - 0.03
coefficient of friction = 0.48
speed at Impact = 25 mph
To determine the V1 speed at the beginning of the skid we have to apply AASTHO
d1 = [tex]( \frac{VA^{2} - VA^{12} }{30(F+N)} )[/tex]
195 = [tex](\frac{VA^2- 25^2}{30(0.48-0.03)} )[/tex]
Hence : VA = 57.075 mph