Answer:
Explanation:
From the information given:
The instantaneous expression of the electric field in the wave is:
[tex]E(r,t)= (i_x \sqrt{3} -i_z) 2 \ sin (2 \pi*10^8t + 2 \pi x/3+2 \pi z /\sqrt{3} + 30 ^0) , \ V/m[/tex]
To determine the unit vector in line with the wave electric field, we take the first term in E(r,t) for [tex]I_E^\to[/tex] as:
[tex]I_E^\to = i_x \sqrt{3}-i_z \\ \\ I_E^\to = \dfrac{i_x \sqrt{3}-i_z}{\sqrt{3 +1}} \\ \\ \mathbf{ I_E = \dfrac{i_x\sqrt{3} -i_z}{2}}[/tex]
The amplitude is denoted by the numerical value after the first term, which is:
[tex]\mathbf{E_o = 2}[/tex]
The wavelength can be determined by using the expression:
[tex]\beta =\dfrac{2 \pi}{\lambda }[/tex]
from the given instantaneous expression:
[tex]\beta = \dfrac{2 \pi}{3}x+\dfrac{2 \pi}{\sqrt{3}}z[/tex]
[tex]\beta = \sqrt{\dfrac{2 \pi}{(3)^2}+\dfrac{(2 \pi}{(\sqrt{3})^2}}[/tex]
[tex]\beta = \sqrt{\dfrac{2 \pi}{9}+\dfrac{2 \pi}{{3}}}[/tex]
Factorizing 2π
[tex]\beta =2 \pi \sqrt{\dfrac{1}{9}+\dfrac{1}{{3}}}[/tex]
[tex]\beta =2 \pi \sqrt{\dfrac{9+3}{9*3}}}[/tex]
[tex]\beta =2 \pi \sqrt{\dfrac{12}{27}}}[/tex]
[tex]\beta =2 \pi \sqrt{\dfrac{4*3}{9*3}}}[/tex]
[tex]\beta =2 \pi \sqrt{\dfrac{4}{9}}}[/tex]
[tex]\beta =2 \pi\times {\dfrac{2}{3}}}[/tex]
recall from the expression using in calculating wavelength:
[tex]\beta =\dfrac{2 \pi}{\lambda }[/tex]
∴
equating both together, we have:
[tex]\dfrac{2 \pi}{\lambda }= 2 \pi\times {\dfrac{2}{3}}}[/tex]
[tex]\lambda = \dfrac{3}{2}[/tex]
λ = 1.5 m
In line with the wave direction; unit vector [tex]i_k[/tex] can be computed as follows:
[tex]i_k = - [ \beta_1x +\beta_2z]/\beta[/tex]
where;
[tex]\beta_1 = \dfrac{2 \pi }{3} \ ; \ \beta_2 = \dfrac{2 \pi }{\sqrt{3}} \ ; \ \beta = \dfrac{2 \pi \times 2}{3} ;[/tex]
∴
[tex]i_k = - \Big[\dfrac{2 \pi}{3}x + \dfrac{2 \pi}{\sqrt{3}} z\Big]\times \dfrac{1}{\dfrac{2 \pi *2}{3}}[/tex]
[tex]i_k = - \Big[\dfrac{x}{2} + \sqrt\dfrac{{3}}{4}} z\Big][/tex]
[tex]i_k = - \Big[\dfrac{1}{2}x + \sqrt{\dfrac{3}{4} }z\Big][/tex]
[tex]\mathbf{i_k = - \Big[0.5x +0.86 z\Big]}[/tex]
quy trình sản xuất bao bì plastic dạng túi
Request for proposal (RFP) is a type of document that contains the information and proposals mostly through the bidding process. This document is regarding the valuable assets, services, entity, commodity, etc.
Answer:
Answer to the following is as follows;
Explanation:
A request for proposal is a documentation that invites prospective contractors to submit business opportunities to an agency or corporation interested in procuring a commodities, product, or valuable resource through a bid procedure.
A request for proposal (RFP) is a commercial document that introduces a project, defines it, and invites eligible contractors to compete on its completion.
A stream of ethylene glycol vapor at its normal boiling point and 1atm flowing at a rate of 175 kg/min is to be condensed at constant pressure. The product stream from the condenser is liquid g lycol at the condensation temperature.
a. Calculate the rate at which heat must be transferred from the condenser (kW).
b. If heat were transferred at a lower rate than that calculated in part (A), what would the state of the product stream be? (Dedu ce as much as you can about the phase and the temperature of the stream.)
c. If heat were transferred at a higher rate than that calculated in part (A), what could you deduce about the state of the product stream?
Answer: hello attached below is the question properly written
a) 2670 Kw
b) product will be made up of vapor and liquid
c) Product will be a super cooled liquid
Explanation:
mass Flow rate ( m ) = 175 kg/min
pressure = 1 atm
molecular weight of ethylene glycol ( mw ) = 62.07 g/mol
enthalpy of vaporization ( ΔHv ) = 56.9 KJ/mol
Using values from the table 8.1 related to the question
a) Determine the rate at which heat must be transferred from condenser
Using values from the table 8.1 related to the question
ΔH = 2670 Kw
b) If heat is transferred at a lower temperature the product will be made up of vapor and liquid
c) If heat was transferred at a higher temperature the product will be a super cooled liquid
An assembly line has 3 fail safe sensors and one emergency shutdown switch.The line should keep moving unless any of the following conditions arise:
(1) If the emergency switch is pressed
(2) If the senor1 and sensor2 are activated at the same time.
(3) If sensor 2 and sensor3 are activated at the same time.
(4) If all the sensors are activated at the same time
Suppose a combinational circuit for above case is to be implemented only with NAND Gates. How many minimum number of 2 input NAND gates are required.
Answer:
1 NAND gate
Explanation:
The minimum number of 2 input NAND gates that can be used to implement the combinational circuit = 1
The only true combinations conditions that can produce a false result ( i.e. condition/result different from the expected result as stated in the question )
Sensor 2 activated + Emergency switch pressed = False ( Line will keep moving )
A test bar of nonferrous material has a diameter of 0.253 inches. Upon applying a tensile load, the sample exhibited 0.002 plastic strain at 3400 lb and the maximum load during testing was 6200 lb and occurred at an engineering strain of 0.65; and breaking occurred at 4400 lb. The sample diameter at fracture was measured to be 0.15 inches.
Required:
a. The yield strength of the material is :________
b. The UTS of the material is:________
Answer:
a. 67607.9psi
b. 123278.33
Explanation:
to get the yield strength of the material
= load/ cross sectional area
cross sectional area = π * 0.253²/4
= 0.0502927
The yield strenght
= 3400/0.0502927
= 67609.9 psi
b. the uts of the material
= maximum load/cross sectional area
= 6200/0.0502927
= 123278.33
The steps for proper studing for the exam. -1 (use: First, Then, Next, After that, Finally)
Answer:
here is your answer
Explanation:
1. First observe the syllabus for all subjects.
2. Then gather all your books
3. For a particular exam read the book related to it ( if possible read early in the morning.
4. After that write the things you learnt by reading.
5. Finally give your exams by giving it all
HOPE IT HELPS......
OM NAMO SHIVAYE
Una canica de masa 15g, con velocidad horizontal de 10 m/s impacta a otra de masa de 8g que se encuentra en el piso y en reposo. Suponga que el movimiento ocurre en la linea que une sus centros. Encuentra la velocidad de cada canica inmediatamente despues de la colision
Answer:
Una canica de masa 15g, con velocidad horizontal de 10 m/s impacta a otra de masa de 8g que se encuentra en el piso y en reposo. Suponga que el movimiento ocurre en la linea que une sus centros. Encuentra la velocidad de cada canica inmediatamente despues de la colisionExplanation:
To convert from the U.S. Customary (FPS) system of units to the SI system of units. A first-year engineering student records three separate measurements as 653 lb, 69.0 mi/h, and 297(106)ft2. Suppose this engineering student has to turn in the results, but the professor only accepts results given in SI units.
Required:
What is the area measurement, 293 (106) ft^2, in SI units?
This question is incomplete, the complete question is;
To convert from the U.S. Customary (FPS) system of units to the SI system of units. A first-year engineering student records three separate measurements as 653 lb, 69.0 mi/h, and 293 × 10⁶ ft². Suppose this engineering student has to turn in the results, but the professor only accepts results given in SI units.
Required:
What is the area measurement, 293 × 10⁶ ft², in SI units?
293 × 10⁶ ft² = ?km²
Answer:
the area measurement is 27.221 km²
Explanation:
Given the data in the question;
What is the area measurement, 293 × 10⁶ ft², in SI units
we are to the result of the measured area from ft² to km²
we know that;
1 meter = 3.2808 ft
1 km = 1000 m
1 ft = (1 / 3.2808)m
1 m = ( 1/1000 ) km
since our measured are is 293 × 10⁶ ft²
hence
A = 293 × 10⁶ × [ (1 / 3.2808)m ]²
A = 27221252.74 m²
A = 27221252.74 × [ ( 1/1000 ) km ]²
A = 27.221 km²
Therefore, the area measurement is 27.221 km²
làm giúp tôi hệ thống truyền lực trên xe toyota
Answer:
ay man ima be real, i just need the points yo
hãy trình bày sự hiểu biết của bạn về đo dòng điện
Answer:
-Khái niệm:
Đo dòng điện là sử dụng các dụng cụ như ôm kê, vôn kế, ampe kế, tần số kế… để xác định các đại lượng vật lý của dòng điện
-Đo lường điện để làm gì?
Phát hiện hư hỏng sự cố trong mạch điện và các thiết bị vi mạch
Xác định các giá trị cần đo
Đánh giá chất lượng của các thiết bị sau sản xuất
Xác định thông số kỹ thuật của thiết bị
-Phân loại dụng cụ đo điện: Hiên nay có 2 phương pháp phân loại chính
a. Theo nguyên lý làm việc
Dụng cụ đo kiểu điện từ
Dụng cụ đo kiểu điện động
Dụng cụ đo kiểu cảm ứng
Dụng cụ đo kiểu từ điện
b. Theo đai lượng, giá trị cần đo
+Đo điện năng: Ví dụ công tơ điện
+Đo điện áp: Ví dụ: Vôn kế
+Đo dòng điện: Ví dụ: Ampe kế
+Đo công suất: Oát kế
+Đo điện trở: Ôm kế
Sai số khi đo: Khi đo lường luôn xảy ra các sai số
Sai số tương đối: Là tỷ lệ % của sự chênh lệch giữa giá trị đo được và giá trị thự
Ideally speaking, bonds tend to form between two particles such that they are separated by a distance where force is exerted on them, and their overall energy is:________
a. a negative, minimized
b. a positive, minimized
c. zero, minimized
d. zero, maximized
e. a positive, maximized
f. a negative, maximized
Answer:
a g i
Explanation:
nnj
Problem
In the clevis shown in Fig. find the minimum bolt diameter and the minimum thickness of each yoke that will support a load P= 14 kips without exceeding a shearing stress of 12 ksi and a bearing stress of 20 ksi
Answer:
In the clevis shown in Fig. 1-11b, find the minimum bolt diameter and the minimum thickness of each yoke that will support a load P = 14 kips without exceeding a shearing stress of 12 ksi and a bearing stress of 20 ksi.
127-clevis-double-shear-bolt.gif
Solution 127
Hide Click here to show or hide the solution
127-fbd-clevis-double-shear-bolt.gifFor shearing of rivets (double shear)
P=τA
14=12[2(14πd2)]
d=0.8618in → diameter of bolt answer
For bearing of yoke:
P=σbAb
14=20[2(0.8618t)]
t=0.4061in → thickness of yoke answer
find the volume of the pond with the following dimension length 40m breadth 10m height 1.2m depth 0.9m express in both meters and feet
Answer:
The volume for this is 29.7
Explanation:
Trust me on this I'm an expert
A circuit diagram for a lighting circuit is shown in Figure 6.
Figure 6
230 V AC
A
RL1
+
B T 12 V
04
4
Explain the function of the relay RL1 in the lighting circuit shown in Figure 6.
[2 marks)
Answer:
is there a picture of the figure?
A balanced star-connected three-phase load is shown in Figure 4. Determine the value of the line currents IR,IY and IB using mesh-current analysis.
Answer:
Therefore the value of the line currents IR, IY, and IB are
[tex]I_{R}=I_{1}=83\angle 6.87^{o}A\\I_{B}=-I_{2}=-71.88\angle-23.13^{o}A\\I_{Y}=I_{2}-I_{1}\\I_{Y}=-I_{2}=41.50\angle113.3^{o}A[/tex]
Explanation:
Apply KVL for loop 1
[tex]415\angle 120^{o}=\left ( 3+j4+3+j4 \right )I_{1}-\left ( 3+j4 \right )I_{2}\\415\angle 120^{o}=\left ( 6+j8 \right )I_{1}-\left ( 3+j4 \right )I_{2}\\415\angle 120^{o}=\left ( 10\angle 53.13^{o} \right )I_{1}-\left ( 5\angle 53.13^{o}\right )I_{2} \rightarrow \left ( 1 \right )[/tex]
Apply KVL for loop 2
[tex]415\angle 0^{o}=\left ( 3+j4+3+j4 \right )I_{2}-\left ( 3+j4 \right )I_{1}\\415\angle 0^{o}=\left ( 6+j8 \right )I_{2}-\left ( 3+j4 \right )I_{1}\\415\angle 0^{o}=\left ( 10\angle 53.13^{o} \right )I_{2}-\left ( 5\angle 53.13^{o}\right )I_{1} \rightarrow \left ( 2 \right )[/tex]
Solving the above equations,
[tex]415\angle 120^{o}+830\angle 0^{o}=\left ( 10\angle 53.13^{o} \right )I_{1}-\left ( 5\angle 53.13^{o}\right )I_{2} +\left ( 20\angle 53.13^{o}\right )I_{2}- \left ( 10\angle 53.13^{o} \right )I_{1}\\415\angle 120^{o}+830\angle 0^{o}=\left ( 20\angle 53.13^{o}\right )I_{2}- \left ( 10\angle 53.13^{o} \right )I_{2}\\415\angle 120^{o}+830\angle 0^{o}=\left ( 10\angle 53.13^{o} \right )I_{2}\\I_{2}= 71.88\angle -23.13^{o}A[/tex]&
[tex]415\angle 0^{o}=\left ( 10\angle 53.13^{o} \right ) \times 71.88\angle -23.13^{o}-\left ( 5\angle 53.13^{o} \right )I_{1}\\415\angle 0^{o}=718.8\angle 30^{o}-\left ( 5\angle 53.13^{o} \right )I_{1}\\\left ( 5\angle 53.13^{o} \right )I_{1}=415\angle 60^{o}\\I_{1}= 83\angle 6.87^{o}A[/tex]
Hence,
[tex]I_{R}=I_{1}=83\angle 6.87^{o}A\\I_{B}=-I_{2}=-71.88\angle-23.13^{o}A\\I_{Y}=I_{2}-I_{1}\\I_{Y}=-I_{2}=41.50\angle113.3^{o}A[/tex]
3. According to the drag equation the velocity of an object moving through a fluid can be modeled by the equation -- -ky- where k is a constant.
(a) Find the general solution to this equation.
(b) An object moving through the water has an initial velocity of 40 m/s. Two seconds later, the velocity has decreased to 30 m/s. What will the velocity be after ten seconds?
A find the ganeral solution to this equation
An object moving through the water has an initial velocity of 40 m/s. Two seconds later, the velocity has decreased to 30 m/s. The velocity after ten seconds is 0.
What is velocity?Velocity is defined as the speed at which an object's position changes in relation to time and a frame of reference. Speed is the rate at which an object travels along a path over time, whereas velocity is the speed and direction of an item's motion. In other words, speed is a scalar value, but velocity is a vector.
As given
Initial velocity = 40 m / sec
Velocity after 2 seconds = 30 m / sec
So the velocity after 10 seconds will be = 0 m / sec
That is the object will stop moving.
Thus. an object moving through the water has an initial velocity of 40 m/s. Two seconds later, the velocity has decreased to 30 m/s. The velocity after ten seconds is 0.
To learn more about velocity, refer to the link below:
https://brainly.com/question/28738284
#SPJ2
Your question is incomplete, but probably your complete question was
From what year did 3.5G enter Vietnam?
Answer:
From what year did 3.5G enter Vietnam?
Explanation:
Vietnam does not have 3.5G network. MobiFone's first trial with 3.5G technology on this band was able to cover the whole waters of Vung Tau and Con Dao in August 2014.
1. What is the maximum value of the linear density in a crystalline solid (linear density defined as the fraction of the line length occupied by atoms, assumed as spheres and only counted it their center is on the line)?
2. What family of directions has the highest linear density in the FCC system?
3. What family of directions has the highest linear density in the BCC system?
4. What family of planes has the highest planar density in the FCC system?
5. What family of planes has the highest planar density in the BCC system?
6. What family of planes has the highest planar density in the HCP sytem?
In the figure below, this “double” nozzle discharges water (at 10°C, density= 1000 kg/m3) into the atmosphere at a rate of 0.50 m3/s. The pressure at the inlet is to be 315612 Pa. If the nozzle is lying in a horizontal plane. Jet A is 10 cm in diameter, jet B is 12 cm in diameter, and the pipe (1) is 30 cm in diameter. The x-component of force (Rx) acting through the flange bolts is required to hold the nozzle in place is:
Solution :
Given data :
p = 315612 Pa
[tex]$V_1=7.07 \ m/sec$[/tex]
At exit of B,
p = [tex]$P_{atm}$[/tex]
[tex]$V_B = 26.1 \ m/sec$[/tex]
At exit of A,
[tex]p=P_{atm}[/tex]
[tex]$V_{A} = 26.1 \ m/s$[/tex]
We need to determine X component of force ([tex]$R_x$[/tex]) to hold in its place.
From figure,
[tex]$\sum F_x = m_0'V_{0x} - m_iV_{ix} $[/tex]
[tex]$=F_x+P_1A_1\sin 30=-mVA-mV_1 \sin 30$[/tex]
[tex]$=F_x=-pA_1\sin 30-m_AV_AA-m_B \sin30$[/tex]
Substitute all the values,
[tex]$=F_x=[-315612 \times \frac{\pi}{4}(0.3)^2 \sin 30]-[26.1 \times 1000 \times 26.1 \frac{\pi}{4}(0.1)^2]-[7.07 \times 1000\times 0.5 \sin 30]$[/tex][tex]$=F_x = -11154.64-5350.21-1767.28$[/tex]
[tex]$F_x = -18.2733 \ kN$[/tex]
Therefore, the force required to hold the nozzle in its place along horizontal direction.
[tex]$F_x = -18.2733 \ kN$[/tex]
many manufacturers currently offer SAE level _________ equipped vehicles
A.2
B.3
C.4
D.5
In a certain pressing operation, the metallic powder fed into the open die has a packing factor of 0.5. The pressing operation reduces the powders to 70% of their starting volume. In the subsequent sintering operation, shrinkage amounts to 10% on a volume basis. Given that these are the only factors that affect the structure of the finished part, determine its final porosity.
Answer:
0.2063
Explanation:
Given data:
packing factor = 0.5
percentage of reduction of powders = 70%
Calculate the final porosity
after sintering Bulk specific volume = 0.9 * 0.7 = 0.63
assuming true specific volume = 1
packing factor = 0.5 , bulk specific volume = 2
packing factor after pressing and sintering
= 1 / ( 2 * 0.63 ) = 0.7937
hence : porosity = 1 - packing factor
= 1 - 0.7937 = 0.2063
Here are the city gas mileages for 13 different midsized cars in 2008. 16, 15, 22, 21, 24, 19, 20, 20, 21, 27 , 18 , 21 , 48 What is the minimum ?
Answer:
Minimum city gas mileage is 15
Explanation:
Minimum city gas mileage among 13 different car sizes in 2008 is 15.
A pressure transducer has the following specifications: Input rage: 0-100 psi and the corresponding Output Range: 0-5 Volts. Linearity Error: 0.10% of the Reading Hysteresis Error: 0.10% of the Reading Sensitivity Error: 0.15% of the Reading Zero Drift Error: 0.20% of the Reading Its output is read via a voltmeter with instrument error of 0.10% of the reading and resolution of 0.01 V. If the applied pressure on the transducer is 65 psi, what is the design stage uncertainty of this pressure measurement system?
Answer:
0.287
Explanation:
Design-stage uncertainty can be expressed as :
Ud = √ Uo^2 + Uc^2 ------ ( 1 )
where : Uo = 1/2( resolution value ) = 1/2 * 0.01 V = 0.005 V
Uc = √(0.10)^2 + (0.10)^2 + (0.15)^2 + (0.20)^2 = 0.287
back to equation 1
Ud = √ ( 0.005)^2 + ( 0.287 )^2 = 0.287
Answer:
0.287
Explanation:
Cite the phases that are present and the phase compositions for the following alloys: (a) 15 wt% Sn - 85 wt% Pb at 100 o C. (b) 1.25 kg of Sn and 14 kg Pb at 200 o C
Answer:
a) ∝ and β
The phase compositions are :
C[tex]_{\alpha }[/tex] = 5wt% Sn - 95 wt% Pb
C[tex]_{\beta }[/tex] = 98 wt% Sn - 2wt% Pb
b)
The phase is; ∝
The phase compositions is; 82 wt% Sn - 91.8 wt% Pb
Explanation:
a) 15 wt% Sn - 85 wt% Pb at 100⁰C.
The phases are ; ∝ and β
The phase compositions are :
C[tex]_{\alpha }[/tex] = 5wt% Sn - 95 wt% Pb
C[tex]_{\beta }[/tex] = 98 wt% Sn - 2wt% Pb
b) 1.25 kg of Sn and 14 kg Pb at 200⁰C
The phase is ; ∝
The phase compositions is; 82 wt% Sn - 91.8 wt% Pb
Csn = 1.25 * 100 / 1.25 + 14 = 8.2 wt%
Cpb = 14 * 100 / 1.25 + 14 = 91.8 wt%
What Is Soil Tunneling?
Answer:
A tunnel built in soft ground—such as clay, silt, sand, gravel or mud—requires specialized techniques compared to hard rock, to compensate for the shifting nature of the soil.
It's from web...
Soft ground tunneling describes the additional measures needed when Microtunneling through soil conditions that are vulnerable to collapse. ... This process ensures tunneling can happen effectively in soft grounds.
It's from me...
The pressure gage on a 2.5-m3 oxygen tank reads 500 kPa. Determine the amount of oxygen in the tank (mass in kg) if the temperature is 28°C and the atmospheric pressure is 97 kPa.
Answer:
[tex]n=5.36kg[/tex]
Explanation:
From the question we are told that:
Volume [tex]V=2.5m^3[/tex]
Pressure[tex]\rho=500Kpa[/tex]
Temperature [tex]T=28^o[/tex]
Atmospheric pressure [tex]\rho_{atm} =97 kPa.[/tex]
Generally the equation for an Ideal gas is mathematically given by
[tex]PV=nRT[/tex]
Therefore
[tex]n=\frac{500*2.5}{8.314*28}[/tex]
[tex]n=5.36kg[/tex]
The calculated value of the thermal conductivity of the carbon nano tube was found as: KCN = 3113 W/m-K, however, the theoretical value of the thermal conductivity of the wire is actually: K = 4500 W/m-K and the island separation is 5 μm (this is the actual spacing between the two islands). The difference between the measured and theoretical values is due to the contact resistance between the nano tube and the islands in the experiment.
Required:
a. Calculate the thermal contact resistance (Rtd) that exists between the carbon nano tube and the top surfaces of the heated and sensing islands.
b. Using the value of thermal contact resistance calculated in part A, calculate the fraction of the total resistance between the heated and sensing islands that is due to the thermal contact resistances for island separation distance of 5, 10, 15, and 20 μm.
Answer:
a) 1,607,973.9 K/W
b)
i) 0.3082 = 30.82%
ii) 0.1821 = 18.21%
iii) 0.1293 = 12.93%
iv) 0.1002 = 10.02%
Explanation:
Value of thermal conductivity ( calculated value ) KCN = 3113 W/m-k
Thermal conductivity ( theoretical value ) K = 4500 W/m-k
Island separation = 5 μm
a) Determine the thermal contact resistance
Resistance due to contact between carbon nano tube and top surfaces can be determined using the relation below
( I / A*K ) + 2Rc = ( l / A*KCN ) ------- ( 1 )
where ; I = 5 * 10^-6 m
A = π * ( 14 * 10^-9 )^2 m^2 = 153.93 * 10^-18 , K = 4500 , KCN = 3113
input values into equation 1 above
hence Rc = 1,607,973.9 K/W
b) Determine fraction of total resistance between heated and sensing
fraction of total resistance ; f1 = [tex]\frac{2 Rc}{I/KA + 2Rc}[/tex]
where : Rc = 1607973.9, K = 4500, A = 153.93 * 10^-18 ,
i) for I = 5 * 10^-6 m
fraction = 0.3082 = 30.82%
ii) for I = 10 * 10^-6 m
fraction = 0.1821 = 18.21%
iii) for I = 15 * 10^-6 m
fraction = 0.1293 = 12.93%
iv) for I = 20*10^-6
fraction = 0.1002 = 10.02%
A heat pump heats the air in a rigid, insulated cuboid room of size 25m x 10m x 4m. The heat pump consumes 15 kW of power. The initial temperature and pressure in this room are 12°C and 1 bar, respectively. With an average coefficient of performance of COPHP= 3.0 over the range of air temperature in this room.
Requried:
How long will it take to raise the temperature in the room to 27 °C?
Answer:
Time required = 287.2 secs
Explanation:
Volume of room = 25 * 10 * 4 = 1000 m^3
power consumed by pump = 15 kW
T1 ( initial temperature ) = 12°C
P1 ( Initial pressure ) = 1 bar
COPhp = 3
Calculate time taken to raise room Temp to 27°C
average heat supplied ( ∅ ) = COPhp * power consumed by pump
= 3 * 15 = 45 kW
Time required can be calculated using the relation below
∅t = P*V*Cv ( T2 - T1 ) [ p = 1.2 kg/m^3 , Cv = 0.718 KJ/kg ( air properties ) ]
45 * 10^3 ( t ) = 1.2*1000* 718 ( 27 - 12 )
∴ solving for t
t = 287.2 secs ≈ 4.79 mins
Your family has asked you to estimate the operating costs of your clothes dryer for the year. The clothes dryer in your home has a power rating of 2250 W. To dry one typical load of clothes the dryer will run for approximately 45 minutes. In Ontario, the cost of electricity is $0.11/kWh. Calculate the costs to run the dryer for your family for one year.
Answer:
The costs to run the dryer for one year are $ 9.03.
Explanation:
Given that the clothes dryer in my home has a power rating of 2250 Watts, and to dry one typical load of clothes the dryer will run for approximately 45 minutes, and in Ontario, the cost of electricity is $ 0.11 / kWh, to calculate the costs to run the dryer for one year the following calculation must be performed:
1 watt = 0.001 kilowatt
2250/45 = 50 watts per minute
45 x 365 = 16,425 / 60 = 273.75 hours of consumption
50 x 60 = 300 watt = 0.3 kw / h
0.3 x 273.75 = 82.125
82.125 x 0.11 = 9.03
Therefore, the costs to run the dryer for one year are $ 9.03.
A drum contains 3 black balls, 5 red balls and 6 green balls. If 4 balls are selected at random what is the probability that the 4 selected contain No red ball
A. 0.1258
B. 0.1587
C. 0.2356
D. 0.2289
Answer:
Probability of no red ball from 4 balls = 0.1258 (Approx.)
Explanation:
Given:
Number of black ball = 3
Number of red ball = 5
Number of green ball = 6
Find:
Probability of no red ball from 4 balls
Computation:
Probability of no red ball from 4 balls = 9c4 / 14c4
Probability of no red ball from 4 balls = 126 / 1001
Probability of no red ball from 4 balls = 0.12587
Probability of no red ball from 4 balls = 0.1258 (Approx.)