Answer:
Answer:4 minutes
Explanation:
Permanent brain damage begins after only 4 minutes without oxygen, and death can occur as soon as 4 to 6 minutes later.
A standard 20° pressure angle, 20 tooth pinion with a diametral pitch of 12 rotates at 1776 rpm driving a mating gear at 740 rpm.a) How many teeth are there on the gear?b) What are the pitch diameters of the pinion and gear?c) What are the standard addendum and dedendum diameters of the pinion and gear?d) What is the theoretically correct center distance?e) What are the radial, tangential and normal tooth loads when contact between the pinion and the gear occurs at the pitch point and the gearset is transmitting ½ hp?
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
what type of address do computer use to find something on network?
ip address
url address
mac address
isp address
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.
What is ISP?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.
What is IP address?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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A balanced three phase source with vL=240 V rms is supplying 8 kVA at 0.6 powder factor lagging to two wye connected parallel loads. If one load draws 3kW at unity powder factor , calculate impedence per phase of the second load.
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
The cross-section of a rough, rectangular, concrete() channel measures . The channel slope is 0.02ft/ft. Using the Darcy-Weisbach friction method, determine the maximum allowable flow rate through the channel to maintain one foot of free board(freeboard is the vertical distance form the water surface to the overtopping level of the channel). For these conditions, find the following characteristics(note that FlowMaster may not directly report all of these):
a) Flow area
b) Wetted perimeter
c) Hydraulic radius(A/P) :
d) Velocity
e) Froude number
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]
A 20-foot-long W10 x 60 is suspended and hanging from one end. If the modulus of elasticity is 29,000 ksi, determine the following.A. What is the maximum tensile stress?
B. What is the maximum normal strain?
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]
What are the Parts of a hydroelectric Power plant ?
Answer:
Trash rack
Open channel
Fore bay
Pen stock
Inlet valve
Turbine
Tailrace
Generator
Power house
When storing used oil, it need to be kept in________ container?
Answer: In a clean plastic or metal container with a tightly sealed lid
what are PAT&E tests on production sysems used for.
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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By balancing information security and access, a completely secure information system can be created.A. TrueB. False
Answer: true
Explanation:
When entering a freeway you should always:
A. Slow down and proceed when it is safe.
B. Stop and make sure there is no traffic approaching.
C. Accelerate to the same speed as the freeway traffic and merge smoothly.
D. Go as fast as you can and swing abruptly into traffic.
The flow rate on an arterial is 1,800 veh/h, evenly distributed over two lanes. If the average speed in these lanes is 40 mi/h, what is the density in veh/h/ln?
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
Calculate the value of ni for gallium arsenide (GaAs) at T = 300 K. The constant B = 3. 56 times 1014 9cm -3 K-3/2) and the bandgap voltage Eg = 1. 42 eV.
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
The steering column connects the steering wheel to the steering gear.
a. True
b. False
The Department of Transportation regulations require which parameter to be recorded on the shipping paper for hazard class Non Flammable Compressed Gases?
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.
1. Round off 2553 N to three significant figures.
2. Round off 58342 m to three significant figures.
3. Round off 68.534 s to three significant figures.
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
Explain why the following acts lead to hazardous safety conditions when working with electrical equipmenta. Wearing metal ring or braceletsb. Being barefootc. Working on a damp concrete floord. Touching grounded conductors while working on electrical equipmente. Working on electrical equipment with sweaty hands
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.
List and describe three classifications of burns to the body.
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:
What is best for a busy student to do for better results in school?
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 ;}
5. One of the major road blocks for direct DC power in residences is the ___. A) generation of DC B) lack of standardization C) difficulty of installation D) quantity of components required for this type of system
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.
what ratio between differential gain and common-mode gain is called
Answer:
CMRR(Common Mode Rejection Ratio) is the ratio of differential gain and the common mode gain.
Explanation:
A proposed piping and pumping system has 20-psig static pressure, and the piping discharges to atmosphere 160 ft above the pump. If the piping friction loss is 20 ft head, the minimum pressure rating (psi) of the piping system is most nearly:
(A) 50
(B) 100
(C) 150
(D) 250
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
List 10 uses for surveying in areas other than land surveying. Select all that apply. a. topographic surveying b. satellite surveying c. aerial surveying d. optical tooling e. marketing surveying f. control surveying g. as-built surveying h. statistical surveying i. telephone surveying j. construction surveying k. alignment surveying l. mine surveying m. solar surveying
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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What tool should be used to loosen or tighten brake or fuel lines?
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.
What is crosshead screws?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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A spherical balloon with a diameter of 9 m is filled with helium at 20°C and 200 kPa. Determine the mole number and the mass of the helium in the balloon.
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:
[tex]P[/tex] - Pressure, in kilopascals.[tex]V[/tex] - Volume, in cubic meters.[tex]R_{u}[/tex] - Ideal gas constant, in kilopascal-cubic meters per kilomole-Kelvin.[tex]T[/tex] - Temperature, in Kelvin.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:
[tex]R[/tex] - Radius of the sphere, in meters. [tex]M[/tex] - Molar mass, in kilograms per kilomole.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.
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A set of experiments is run on an op amp that is ideal except for having a finite gain A. The results are tabulated below. Are the results consistent? If not, are they reason-able, in view of the possibility of experimental error? What do they show the gain to be? Using this value, predict values I of the measurements that were accidentally omitted (the blank entries).Experiment # v1 v2 vo 1 0.00 0.00 0.00 2 1.00 1.00 1.00 3 1.00 1.00 4 1.00 1.10 10.1 5 2.01 2.00 -0.99 6 1.99 2.00 1.00 7 5.10 -5.10
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
6, Large, centralized power-generating stations are often located near ___. A) areas without natural energy sources B) abundant energy sources C) metropolitan areas D) rural areas
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.
The Stokes-Oseen formula for drag force F on a sphere of diameter D in a fluid stream of low velocity V, density p and viscosity μ is
F=3πμDV+9π/16∗pV2d2
Is this formula dimensionally homogenous?
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.
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
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]
What should you do before you start welding?
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.
A civil engineer designs a wheelchair accessible ramp next to a set of steps leading up to a building. The height from the ground to the top of the stairs is 3ft. Based on ADA codes, the slope must be 1:12 or less. (Slope is equal to the rise of the ramp divided by the run of the ramp.) What is the IMA of this ramp if the engineer uses a slope of 1:12?
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