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3 years ago

What is the function of engineers?

Engineering

1 answer:

lara [203]3 years ago

5 0

Answer:

To add technology and advancements to society and make out community more advanced.

Explanation:

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One kilogram of air, initially at 5 bar, 350 K, and 3 kg of carbon dioxide (CO2), initially at 2 bar, 450 K, are confined to opp

pentagon [3]

Answer:

Check the explanation

Explanation:

Energy alance of 2 closed systems: Heat from CO2 equals the heat that is added to air in

$m_{a} c_{v,a}(T_{eq} -T_{a,i)} =m_{co2} c_{v,co2} (T_{co2,i} -T_{eq)}$

1x0.723x $(T_{eq} -350)$ =3x0.780x $(450-T_{eq} )$ ⇒ $T_{eq}$ = 426.4 °K

The initail volumes of the gases can be determined by the ideal gas equation of state,

$V_{a,i} = \frac{mRT_{a,i} }{P_{a,i} }$ = $\frac{1x (8.314 28.97 kJ kg • °K)x 350°K}{5 bar x 100KPa bar}$ = 0.201 $m^{3}$

The equilibrium pressure of the gases can also be obtained by the ideal gas equation

$P_{eq=\frac{(m_{a}R_{a}T_{eq})+(m_{a}R_{a}T_{eq} ) }{(V_{a,eq}+V_{CO2,eq)} } =\frac{(m_{a}R_{a}T_{eq})+(m_{a}R_{a}T_{eq} ) }{(V_{a,i}+V_{CO2,i)} }$

$P_{eq}$ = 1x(8.314 28.97)x426.4+3x(8.314 44)x426.4

(0.201+1.275)

= 246.67 KPa = 2.47 bar

6 0

3 years ago

A rectangular conductor with a cross sectional area of 1.04 square millimeters (mm) ^2 has a resistance of 0.075 ohms. What woul

kogti [31]

Answer:

0.0375 ohms

Explanation:

The resistance of a material is the product of the resistivity of the material by the length of the material divided by its cross-section area.

Mathematically,

resistance= resistivity × length/area

In this case the resistivity of the material is the same, and the length is the same thus, assume a length of 1 unit, the cross-section area is the one changing

In applying the formula,

resistivity is r and length is l=1 unit, find the resistivity the material as;

resistance= resistivity * length /area

0.075=r*1/1.04

0.075=r*0.9615

0.075/0.9615 =r

r=0.078

use the r=0.078 , a length of 1 unit (assumed), and area of 2.08 mm² to find the new resistance

Resistance= resistivity * length /area

Resistance = 0.078*1/2.08

Resistance= 0.078 * 0.4807 = 0.0375 ohms

Point to note here is that the greater the cross-section area, the less the resistance.

4 0

3 years ago

The real power delivered by a source to two impedances, ????1=4+????5⁡Ω and ????2=10⁡Ω connected in parallel, is 1000 W. Determi

kirza4 [7]

Answer:

The question is incomplete, below is the complete question

"The real power delivered by a source to two impedance, Z1=4+j5⁡Ω and Z2=10⁡Ω connected in parallel, is 1000 W. Determine (a) the real power absorbed by each of the impedances and (b) the source current."

answer:

a. 615W, 384.4W

b. 17.4A

Explanation:

To determine the real power absorbed by the impedance, we need to find first the equivalent admittance for each impedance.

recall that the symbol for admittance is Y and express as

$Y=\frac{1}{Z}$

Hence for each we have,

$Y_{1} =1/Zx_{1}\\Y_{1} =\frac{1}{4+j5}\\converting to polar \\ Y_{1} =\frac{1}{6.4\leq 51.3}\\ Y_{1} =(0.16 \leq -51.3)S$

for the second impedance we have

$Y_{2}=\frac{1}{10}\\Y_{2}=0.1S$

we also determine the voltage cross the impedance,

P=V^2(Y1 +Y2)

$V=\sqrt{\frac{P}{Y_{1}+Y_{2}}}\\$

$V=\sqrt{\frac{1000}{0.16+0.1}}\\ V=62v$

The real power in the impedance is calculated as

$P_{1}=v^{2}G_{1}\\P_{1}=62*62*0.16\\ P_{1}=615W$

for the second impedance

$P_{2}=v^{2}*G_{2}\\ P_{2}=62*62*0.1\\384.4w$

b. We determine the equivalent admittance

$Y_{total}=Y_{1}+Y_{2}\\Y_{total}=(0.16\leq -51.3 )+0.1\\Y_{total}=(0.16-j1.0)+0.1\\Y_{total}=0.26-J1.0\\$

We convert the equivalent admittance back into the polar form

$Y_{total}=0.28\leq -19.65\\$

the source current flows is

$I_{s}=VY_{total}\\I_{s}=62*0.28\\I_{s}=17.4A$

6 0

3 years ago

The water in a large lake is to be used to generate electricity by the installation of a hydraulic turbine-generator at a locati

Lynna [10]

Answer:

a) 0.76

b) 0.80

c) 1964 kW

Explanation:

GIVEN DATA:

$\dot m = 5000 kg/s$

Assume Mechanical energy at exist is negligible

A) Take lake bottom as reference, and then kinetic and potential energy are taken as zero.

change in mechanical energy is givrn as

$e_{in} - e_{out} = \frac{P}{\rho} - 0 = gh = 9.81 \times 50( \frac{1 kJ/kg}{1000 m^2/s^2}$

= 0.491 kJ/kg

$\Delta \dot E_{mec} = \dot m (e_{in} - e_{out}) = 5000 \times 0.491 = 2455 kW$

$\eta_{OVERALL} = \frac{\dot W}{\Delta \dot E_{mec}} = \frac{1862}{2455} = 0.76$

B) $\eta -{gen} = \frac{\eta_{overall}}{\eta_{gen}} = \frac{0.76}{0.95} = 0.80$

c) $\dot W_{shaft} = \eta_{overall} \left | \Delta \dot E_{mec} \right | = 0.80(2455)$

$\dot W_{shaft} = 1964 kW$

7 0

4 years ago

You were recently hired by the Andrews CEO as a consultant to evaluate the performance of the Chief Financial Officer (CFO). As

goldfiish [28.3K]

Answer: Collect more information about the extent to which this reported behavior is impacting others

Explanation:

The options are:

a. Collect more information about the extent to which this reported behavior is impacting others.

b. Tell the CEO about what you have uncovered and ask for her permission to speak about it with the CFO.

c. Focus on the CFO’s work performance since his personal behavior is inappropriate in the workplace.

d. Inform the human resources department that there is a potential problem.

Given the information provided in the question, the most effective next step in the process will be to collect more information about the extent to which this reported behavior is impacting others. This will be vital in determining whether what is being said about the Chief Financial Officer is true or not and also to know if true, whether it has an affect on the performance of affected employees in the organization.

Option B is wrong as telling the CEO right away isn't the next step as adequate information must be gathered first.

Option C is also wrong as the focus shouldn't be on his work in the organization alone. His personal behavior should be addressed as well if he's wrong. A great organization is made up of great individuals with good behaviors.

Option D is also wrong as the next step should not be to inform the human resource.

Therefore, the correct option is A.

5 0

3 years ago