when breathing or the heart has stopped, brain damage can occur within___ minutes

This question is incomplete, the complete question is;

Calculate the value of ni for gallium arsenide (GaAs) at T = 300 K.

The constant B = 3.56×10¹⁴ (cm⁻³ K^-3/2) and the bandgap voltage E = 1.42eV.

Answer: the value of ni for gallium arsenide (GaAs) is 2.1837 × 10⁶ cm⁻³

Explanation:

Given that;

T = 300k

B = 3.56×10¹⁴ (cm⁻³ K^-3/2)

Eg = 1.42 eV

we know that, the value of Boltzmann constant k = 8.617×10⁻⁵ eV/K

so to find the ni for gallium arsenide;

ni = B×T^(3/2) e^ ( -Eg/2kT)

we substitute

ni = (3.56×10¹⁴)(300^3/2) e^ ( -1.42 / (2× 8.617×10⁻⁵ 300))

ni =  (3.56×10¹⁴)(5196.1524)e^-27.4651

ni = (3.56×10¹⁴)(5196.1524)(1.1805×10⁻¹²)

ni = 2.1837 × 10⁶ cm⁻³

Therefore the value of ni for gallium arsenide (GaAs) is 2.1837 × 10⁶ cm⁻³

Answer:

b. satellite surveying

c. aerial surveying

d. optical tooling

e. marketing surveying

f. control surveying

h. statistical surveying

i. telephone surveying

k. alignment surveying

l. mine surveying

m. solar surveying

Explanation:

A Survey is an act of examination of the features of a subject or material under consideration. Land surveying refers to the examination of the natural and man-made features of a piece of land using scientific and mathematical methods.

Land surveying finds application in construction where a survey is made on all the structures found in a constructed property. Topographic surveying deals with examining the natural and man-made feature of a piece of land. As-built survey as the name implies examines the features and location of a building during or recently after construction. These three are examples of land surveys.

Some type of surveying other than land surveying includes satellite, aerial, optical tooling, marketing, control surveying, statistical, telephone, alignment, mine, and solar surveying

A Survey means an examination of a features, subject or material under consideration.

Land surveying refers to the examination of the natural and man-made features of a piece of land using scientific and mathematical methods.

However, some other type of surveying other than land surveying includes satellite, aerial, optical tooling, marketing, control surveying, statistical, telephone, alignment, mine, and solar surveying.

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Answer:

Trash rack

Open channel

Fore bay

Pen stock

Inlet valve

Turbine

Tailrace

Generator

Power house

Answer:

i)The results are consistent at ; Rows ( 1,2,4,6 ), which simply means that it is fairly consistent and makes sense

ii) Row 5 shows a gain of -99 which is ≈ -100 and there is a possibility of experimental error of (1%)

ii ) The omitted values are : row 3 = 0.99, Row 7 = 5.049

Explanation:

To calculate/determine the missing/omitted values we have to apply this formula:

Vo = ( V1 - V2 ) G

Vo = output = 1

G = gain = - 100

V1 =

we find  V1 along line 3 ( row 3 )

(V1 - V2) G = 1

( V1 - 1 ) * -100 = 1

hence V1 = 0.99

we find V2 along row 7

( V1 - V2 ) G = 1

( 5.10 - V2 ) * -100 = 1

hence V2 = 5.049

Answer:

2.35 + j8.34 Ω

Explanation:

Voltage = V[tex]_{L}[/tex] = 240 V rms

supplying power = S[tex]_{s}[/tex] = 8 kVA

power factor = pf[tex]_{s}[/tex] = 0.6

Let P₁ represents one load draws 3kW at unity powder factor

The power angle is:

θ[tex]_{s}[/tex] = cos⁻¹  pf[tex]_{s}[/tex] = cos⁻¹  0.6 = 53.13°

Complex power supplied source is:

S[tex]_{s}[/tex] =  S[tex]_{s}[/tex] < θ[tex]_{s}[/tex] = 8<53.13° kVA

Complex power for first load:

S₁ = P₁ = 3kVA

Since the power angle of first load is  θ₁ = 0°

According to principle of conservation of AC power, the power of second load is:

S₂ =  S[tex]_{s}[/tex] - S₁

    = 8<53.13° - 3

    = 6.65<74.29° kVA

Since the second load is a Y connected load the phase voltage:

V[tex]_{p}[/tex] =  V[tex]_{L}[/tex] / [tex]\sqrt{3}[/tex]

    = 240/1.732051

    = 138.564

    = 138.56 V

Complex power of second load:

S₂ = 3 V[tex]_{p}[/tex]² / Z[tex]_{p}[/tex]

impedance per phase of the second load:

Z[tex]_{p}[/tex] =  3 V[tex]_{p}[/tex]² / S₂

   = 3 (138.56)² /  6.65<74.29°

   = 3(19198.8736) / 6.65<74.29°

   = 57596.6208 / 6.65<74.29°

Z[tex]_{p}[/tex] = 2.35 + j8.34Ω

Answer: true

Explanation:

Answer:

number of mole is 31342.36 moles

mass is 125.369 kg

Explanation:

Diameter of the spherical balloon d = 9 m

radius r = d/2 = 9/2 = 4.5 m

The volume pf the sphere balloon ca be calculated from

V = [tex]\frac{4}{3} \pi r^3[/tex]

V = [tex]\frac{4}{3}* 3.142* 4.5^3[/tex] = 381.75 m^3

Temperature of the gas T = 20 °C = 20 + 273 = 293 K

Pressure of the helium gas = 200 kPa = 200 x 10^3 Pa

number of moles n = ?

Using

PV = nRT

where

P is the pressure of the gas

V is the volume of the gas

n is the mole number of the gas

R is the gas constant = 8.314 m^3⋅Pa⋅K^−1⋅mol^−1

T is the temperature of the gas (must be converted to kelvin K)

substituting values, we have

200 x 10^3 x 381.75 = n x 8.314 x 293

number of moles n  = 76350000/2436 = 31342.36 moles

We recall that n = m/MM

or m = n x MM

where

n is the number of moles

m is the mass of the gas

MM is the molar mass of the gas

For helium, the molar mass = 4 g/mol

substituting values, we have

m = 31342.36 x 4

m = 125369.44 g

m = 125.369 kg

The mole number and the mass of the helium in the balloon are 250.801 kilomoles and 1003.706 kilograms, respectively.

Let suppose that helium contained in the spherical balloon behaves ideally, the mole number ([tex]n[/tex]), in kilomoles, is determined by the following expression:

[tex]n = \frac{P\cdot V}{R_{u}\cdot T}[/tex] (1)

Where:

The volume and mass of helium ([tex]m[/tex]), in kilograms, is described by these two formulas:

[tex]V = \frac{4\pi}{3}\cdot R^{3}[/tex] (2)

[tex]m = n\cdot M[/tex] (3)

Where:

If we know that [tex]P = 200\,kPa[/tex], [tex]R = 9\,m[/tex], [tex]R_{u} = 8.314\,\frac{kPa\cdot m^{3}}{kmol\cdot K}[/tex], [tex]T = 293.15\,K[/tex] and [tex]M = 4.002\,\frac{kg}{kmol}[/tex], then the mole number and the mass of the helium in the balloon are:

[tex]V = \frac{4\pi}{3}\cdot (9\,m)^{3}[/tex]

[tex]V \approx 3053.628\,m^{3}[/tex]

[tex]n = \frac{(200\,kPa)\cdot (3053.628\,m^{3})}{\left(8.314\,\frac{kPa\cdot m^{3}}{kmol\cdot K} \right)\cdot(293.15\,K)}[/tex]

[tex]n = 250.580\,kmol[/tex]

[tex]m = (250.801\,kmol)\cdot \left(4.002\,\frac{kg}{kmol} \right)[/tex]

[tex]m = 1003.706\,kg[/tex]

The mole number and the mass of the helium in the balloon are 250.801 kilomoles and 1003.706 kilograms, respectively.

We kindly invite to check this question on ideal gases: https://brainly.com/question/16211117

Answer:

[tex]\frac{ML}{T^2}=\frac{ML}{T^2}[/tex]

Hence it is proved that Stokes-Oseen formula is dimensionally homogenous.

Explanation:

For equation to be dimensionally homogeneous both side of the equation must have same dimensions.

For given Equation:

F= Force, μ= viscosity, D = Diameter, V = velocity, ρ= Density

Dimensions:

[tex]F=\frac{ML}{T^2}[/tex]

[tex]\mu=\frac{M}{LT}[/tex]

[tex]D=L\\\\V=\frac{L}{T}\\ \\\rho=\frac{M}{L^3}[/tex]

Constants= 1

Now According to equation:

[tex]\frac{ML}{T^2}=[\frac{M}{LT}][L] [\frac{L}{T}] + [\frac{M}{L^3}][\frac{L^2}{T^2}][L^2][/tex]

Simplifying above equation, we will get:

[tex]\frac{ML}{T^2}=2*\frac{ML}{T^2}[/tex]

Ignore "2" as it is constant with no dimensions. Now:

[tex]\frac{ML}{T^2}=\frac{ML}{T^2}[/tex]

Hence it is proved that Stokes-Oseen formula  is  dimensionally homogenous.

Answer:

(a) the maximum tensile stress is 68.2 psi

(b) the maximum normal strain is 2.35 x 10⁻⁶

Explanation:

Given;

modulus of elasticity, E = 29,000 ksi = 29 x 10⁶ psi

(a) the maximum tensile stress

[tex]\tau = \frac{f}{A}[/tex]

f is the maximum force suspended = 20 x 60 = 1200 lb

A is the area of W10 x 60 = 17.6 in²

[tex]\tau = \frac{1200}{17.6} \\\\\tau = 68.2 \ psi[/tex]

(b) the maximum normal strain.

According to Hook's law stress is directional to strain

τ = Eε

[tex]\epsilon = \frac{\tau}{E}\\\\\epsilon = \frac{68.2}{29*10^{6}}\\\\\epsilon = 2.35*10^{-6}[/tex]

Answer:

A) 48

B) Pitch diameters : pinion = 42.164 mm, Gear = 101.19 mm

C) standard addendum : pinion = 46.3804, Gear = 105.406

    standard dedendum : pinion = 37.265 mm, Gear = 96.312 mm

D) 71.672 mm

E) 94.989 N , 101.0858 N,  34.573 N

Explanation:

Given Data :

∅ = 20⁰ , Tp = 20 ( tooth pinion ),

diameter pitch = 12, Np = 1776 rpm ,

Ng = 740 rpm,

attached below is the detailed solution of the given problems

Answer: (B) 100

Explanation:

Given that;

Pstatic = 20 psig , hz = 160ft, hf = 20ft

Now total head will be;

T.h = hz + hf

T.h= 160 + 20

T.h = 180ft

Minimum pressure = Psatic + egh

we know that specific weight of water is 62.4 (lb/ft3)

so

P.min = (20 bf/in² ) + (62.4 b/ft³ × 180 fr

P.min = (20 bf/in² ) + ( 62.4 × 180 × 1 ft²/144 in²)

P.min = 20 + 78

P.min = 98 lbf/in²

Therefore the minimum pressure rating (psi) of the piping system is most nearly B) 100

Using

q = k*v,

where q = traffic flow rate, k = density, v = space mean speed.

so, 1800 = k x 40

so, k = 1800/40 = 45 veh/mie on two lanes,

so k = 45/2 = 22.5veh/h/in

Answer:

Portable appliance testing (PAT) is the term used to describe the examination of electrical appliances and equipment to ensure they are safe to use. Most electrical safety defects can be found by visual examination but some types of defect can only be found by testing.

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Answer: abundant energy sources

Explanation:

A power generating station which is sometimes referred to as the power plant is simply an industrial facility that is used for the generation of power.

Large, centralized power-generating stations are often located near abundant energy sources. It should be noted that most power stations burn fossil fuels like oil, coal, natural gas, in order to be able to generate power and hence, they have to be located where there's abundance of the energy sources.

Explanation:

1. Weld only in authorized areas. Make sure the area is dry, chemical free, and well ventilated.

2. Inspect the equipment before starting to use it.

3. Keep other people away, unless they are authorized to be there and are wearing the appropriate personal protective equipment.

Answer:

D) quantity of components required for this type of system

Explanation:

Electricity can be transmitted using the alternating and direct currents. The alternating current is one in which the flow of the current diverts at certain time intervals whereas, the direct current is one in which there is a constant one-directional flow of current. The DC is used in batteries and solar panels. Residential areas and business places make use of the AC current.

One of the several reasons why the DC is not used in homes is because unlike the AC it is not easy to build and sustain. Moreso, it has more components compared to the AC. For example, its motor consists of brushes and commutators . The components, example, switches are also large compared to the AC components.

Answer:

The answer is below

Explanation:

A 4-pole, 3-phase induction motor operates from a supply whose frequency is 60 Hz. calculate: 1- the speed at which the magnetic field of the stator is rotating. 2- the speed of the rotor when the slip is 0.05. 3- the frequency of the rotor currents when the slip is 0.04. 4- the frequency of the rotor currents at standstill.

Given that:

number of poles (p) = 4, frequency (f) = 60 Hz

1) The synchronous speed of the motor is the speed at which the magnetic field of the stator is rotating. It is given as:

[tex]n_s=\frac{120f}{p}=\frac{120*60}{4}=1800\ rpm[/tex]

2) The slip (s) = 0.05

The speed of the motor (n) is the speed of the rotor, it is given as:

[tex]n=n_s-sn_s\\\\n=1800-0.05(1800)\\\\n=1800-90\\\\n=1710\ rpm[/tex]

3) s = 0.04

The rotor frequency is the product of the supply frequency and slip it is given as:

[tex]f_r=sf\\\\f_r=0.04*60\\\\f_r=2.4\ Hz[/tex]

4) At standstill, the motor speed is zero hence the slip = 1:

[tex]s=\frac{n_s-n}{n_s}\\ \\n=0\\\\s=\frac{n_s-0}{n_s}\\\\s=1[/tex]

The rotor frequency is the product of the supply frequency and slip it is given as:

[tex]f_r=sf\\\\f_r=1*60\\\\f_r=60\ Hz[/tex]

Answer:

The following are the answer to this question:

Explanation:

In point a, Calculating the are of flow:

[tex]\bold{Area =B \times D_f}[/tex]

         [tex]=6\times 5\\\\=30 \ ft^2[/tex]

In point b, Calculating the wetter perimeter.

[tex]\bold{P_w =B+2\times D_f}[/tex]

      [tex]= 6 +2\times (5)\\\\= 6 +10 \\\\=16 \ ft[/tex]

In point c, Calculating the hydraulic radius:

[tex]\bold{R=\frac{A}{P_w}}[/tex]

   [tex]=\frac{30}{16}\\\\= 1.875 \ ft[/tex]

In point d, Calculating the value of Reynolds's number.

[tex]\bold{Re =\frac{4VR}{v}}[/tex]

     [tex]=\frac{4V \times 1.875}{1 \times 10^{-5} \frac{ft^2}{s}}\\\\[/tex]

     [tex]=750,000 V[/tex]

Calculating the velocity:

[tex]V= \sqrt{\frac{8gRS}{f}}[/tex]

   [tex]= \sqrt{\frac{8\times 32.2 \times 1.875 \times 0.02}{f}}\\\\=\frac{3.108}{\sqrt{f}}\\\\[/tex]

[tex]\sqrt{f}=\frac{3.108}{V}\\\\[/tex]

calculating the Cole-brook-White value:

[tex]\frac{1}{\sqrt{f}}= -2 \log (\frac{K}{12 R} +\frac{2.51}{R_e \sqrt{f}})\\\\ \frac{1}{\frac{3.108}{V}}= -2 \log (\frac{2 \times 10^{-2}}{12 \times 1.875} +\frac{2.51}{750,000V\sqrt{f}})\\[/tex]

[tex]\frac{V}{3.108} =-2\log(8.88 \times 10^{-5} + \frac{3.346 \times 10^{-6}}{750,000(3.108)})[/tex]

After calculating the value of V it will give:

[tex]V= 25.18 \ \frac{ft}{s^2}\\[/tex]

In point a, Calculating the value of Froude:

[tex]F= \frac{V}{\sqrt{gD}}[/tex]

[tex]= \frac{V}{\sqrt{g\frac{A}{\text{Width flow}}}}\\[/tex]

[tex]= \frac{25.18}{\sqrt{32.2\frac{30}{6}}}\\\\= \frac{25.18}{\sqrt{32.2 \times 5}}\\\\= \frac{25.18}{\sqrt{161}}\\\\= \frac{25.18}{12.68}\\\\= 1.98[/tex]

The flow is supercritical because the amount of Froude is greater than 1.  

Calculating the channel flow rate.

[tex]Q= AV[/tex]

   [tex]=30x 25.18\\\\= 755.4 \ \frac{ft^3}{s}\\[/tex]

Answer: IMA = 12.042

Explanation:

Given that;

Height from the ground h is 3 ft

Slope of ramp s is 1:12

Horizontal length of the ramp x will be 3 × 12 = 36 ft

Now to get the IMA ( ideal mechanical advantage,)

IMA = length of the ramp over / height of the ramp

IMA = (√( 36² + 3²)) / 3

IMA = (√ 1305 ) / 3

IMA = 36.124 / 3

IMA = 12.042

Answer: In a clean plastic or metal container with a tightly sealed lid

Answer:

Number of cylinders of each gas

Explanation:

The Department of Transportation regulations Title 49 of the United States Code of Federal Regulations specifies that the number of cylinders of each gas being transported should be recorded on the shipping paper for gases classified under hazard class 2.2 of which one of them are the Non Flammable compressed gases.

The definition of gases in division 2.2 encompasses compressed gas, liquefied gas, compressed gas in solution, asphyxiant gas and oxidizing gas. They must meet the absolute pressure of 280kPa or greater at 20 degree Celsius.

Answer:

Please find the answer in the explanation

Explanation:

In Engineering, safety is very essential and very important for all engineers to stick to.

A.) Wearing metal ring or bracelets.

When their is discharg of electrical charges, wearing of metal rings or braceletsb can allow charges to pass through them into the body which can eventually lead to electrical shock.

B.) Being barefoot

Being bare footed is very dangerous because someone can mistakenly step on naked wire which can lead to electrical shock.

C. Working on a damp concrete floor.

It is very hazardous to be working on a damp concrete floor because of the water moisture. It is very unsafe for any electrical job to be done on any wet area because water can conduct electricity which can lead to electrical shock.

d. Touching grounded conductors while working on electrical equipment

Grounded conductor can allow charges to flow through them. So, it is very unsafe to have them have contact with the body because of electrical charges.

e. Working on electrical equipment with sweaty hands

A sweaty hands contain some content of water which can conduct electricity and lead to electrical shock.

Answer:

(1) 2553 N = 2550 N

(2) 58342 m = 58300 m

(3) 68.534 s = 68.5 s

Explanation:

To round off a number to any significant number start from the last digit, round it off to 1 if the number is up to 5 and to 0 if the last digit is less than 5. Add this 1 or 0 to the preceding digit and continue the process until you are left with three non zero digits, if you are rounding off to three significant figures.

(1) Round off 2553 N to three significant figures.

= 2550 N

(2) Round off 58342 m to three significant figures.

= 58300 m

(3) Round off 68.534 s to three significant figures.

= 68.500 s (zero after decimal point is insignificant)

= 68.5 s

The tool you would use are brake line wrenches.

The tool should be used to loosen or tighten brake or fuel the lines the tool you would use are brake line wrenches.

A crosshead screw is simple metal machine that can be used to fasten one object to another. They have an X–shaped slot at the head of the screw where the screwdriver is inserted. Phillips Head Screwdriver can be used to loosen or tighten crosshead screws.

The Philips head screwdriver is a perfect instrument that can be used to loosen or tighten crosshead screws when fastening an object onto another one. The Philips head screwdriver should be the same as the width of slotted screw head in order to fit onto the head of the screw.

Therefore, The tool should be used to loosen or tighten brake or fuel the lines the tool you would use are brake line wrenches.

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Answer:

Set high and clear expectations for quality work

Don't attempt to cram all your studying into one session

Explanation:

Participate in Class

eat a well balanced diet

Find perfect place to Study.

HavE a NIce dAY ;}

Answer:

CMRR(Common Mode Rejection Ratio) is the ratio of differential gain and the common mode gain.

Explanation:

Answer:

The answer would be ISP address

Explanation:

An Internet Protocol address is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. An IP address serves two main functions host or network interface identification and location addressing which can help you a lot.

The type of address the computer use to find something on network is ISP address.

ISP is simply Internet service provider. They are companies which provides internet services to people. They charge based on the quantity of their service used at a particular time. ISP companies also provide softwares for its users.

An Internet Protocol address refers to a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.

Therefore, the correct answer is option D

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AnswerWhat Are the Classifications of Burns? Burns are classified as first-, second-, or third-degree, depending on how deep and severe they penetrate the skin's surface. First-degree burns affect only the epidermis, or outer layer of skin. The burn site is red, painful, dry, and with no blisters.

Explanation:

Answer:

AnswerWhat Are the Classifications of Burns? Burns are classified as first-, second-, or third-degree, depending on how deep and severe they penetrate the skin's surface. First-degree burns affect only the epidermis, or outer layer of skin. The burn site is red, painful, dry, and with no blisters.

Explanation: