1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Nesterboy [21]
1 year ago
10

By the end of the day, a 45 ft x 25 ft x 8 ft office has a carbon dioxide air level of 1,100 ppm. Determine the time in hours ne

cessary to reduce this concentration to ambient levels (approximately 325 ppm) assuming 20% of the return is "fresh" makeup air and there are two air changes per hour.
Engineering
1 answer:
Julli [10]1 year ago
6 0

The total hours that are necessary to reduce carbon dioxide level to at least 325 ppm are 4 hours.

<h3>How does carbon dioxide concentration change over time?</h3>

First hour:

  • 1,100 - 20 %
  • 1,100 - 220 = 880

  • 880 - 20%
  • 880 - 176 = 704

Second hour:

  • 704 - 20%
  • 704 - 140.8 =663.2

  • 663.2 - 20%
  • 663.2 - 132.64 = 530.56

Third hour:

  • 530.56 - 20%
  • 530.56 - 106.112 = 424.44

  • 424.44 - 20%
  • 424.44 - 84.88 = 339.55

Fourth hour:

  • 339.55 - 20%
  • 339.55 - 67.91 = 271.64

Learn more about carbon dioxide in: brainly.com/question/3049557

#SPJ1

You might be interested in
Independent auto lots usually have ____ finance rates than dealerships
wel

Independent auto lots usually have <u>higher</u> finance rates than dealerships

<u>Explanation:</u>

The finance rates that are charged by the dealers are lower than the finance charges that are charged by the independent auto. In case if you are getting financed through dealerships, you can also negotiate with them to charge finance rates and lower the charges of the finance.

But this negotiation and lowering of the finance rates is not possible with the independent auto lots and thus they charge higher rates compared to the dealerships.

8 0
3 years ago
A DC generator turns at 2000 rpm and has an output of 200 V. The armature constant is 0.5 V-min/Wb, and the field constant of th
WITCHER [35]

Answer:

b. 10A

Explanation:

Using the formula, E= k × r×I

200= 0.5 ×2000×0.02×I

200=20×I

Dividing with 20

I = 200/20= 10A

4 0
3 years ago
Read 2 more answers
Why do we need an architect?explain briefly by focusing on its various sectors.
lara [203]

Answer:

An architect will help you determine exactly what you need and come up with inventive ideas to solve even the most complex design problems. Think of us as professional 3D problem solvers! An architect can and should lift your project out of the ordinary.

Explanation:

What are the 3 main functions of an architect?

Design: Architects must design, plan, and develop concepts to create construction plans and technical documents. These are based on client requirements and ideas. Research: Architects must learn about the different building codes, safety regulations, construction innovations and city laws that affect their designs

What are the 7 types of architecture?

There are several main types of architects who focus on different types of structures and designs.

...

Commercial Architects

Office buildings / skyscrapers.

Hotels.

Bridges.

Schools.

Museums.

Government buildings.

Multi-unit residential buildings.

Pretty much any type of building that's not a residential home.

8 0
2 years ago
A loss in value caused by an undesirable or hazardous influence offsite is which type of depreciation?
Lubov Fominskaja [6]

External depreciation may be defined as a loss in value caused by an undesirable or hazardous influence offsite.

<h3>What is depreciation?</h3>

Depreciation may be defined as a situation when the financial value of an acquisition declines over time due to exploitation, fray, and incision, or obsolescence.

External depreciation may also be referred to as "economic obsolescence". It causes a negative influence on the financial value gradually.

Therefore, it is well described above.

To learn more about Depreciation, refer to the link:

brainly.com/question/1203926

#SPJ1

5 0
1 year ago
A three-phase wye-connected synchronous generator supplies a network through a transmission line. The network can absorb or deli
Amanda [17]

Answer:

the graph and the answer can be found in the explanation section

Explanation:

Given:

Network rated voltage = 24 kV

Impedance of network = 0.07 + j0.5 Ω/mi, 8 mi

Rn = 0.07 * 8 = 0.56 Ω

Xn = 0.5 * 8 = 4 Ω

If the alternator terminal voltage is equal to network rated voltage will have

Vt = 24 kV/√3 = 13.85 kV/phase

The alternative current is

I_{a} =\frac{40x10^{6} }{\sqrt{3}*24x10^{3}  } =926.2A

X_{s} =0.85\frac{13.85}{926.2} =12.7ohm

The impedance Zn is

\sqrt{0.56^{2}+4^{2}  } =4.03ohm

The voltage drop is

I_{a} *Z_{n} =926.2*4.03=3732.58V

r_{dc} =\frac{voltage}{2*current} =\frac{13.85}{2*926.2} =7.476ohm

rac = 1.2rdc = 1.2 * 7.476 = 8.97 Ω

The effective armature resistance is

Z_{s} =\sqrt{R_{a}^{2}+X_{s}^{2}    } =\sqrt{8.97^{2}+12.7^{2}  } =15.55ohm

The induced voltage for leading power factor is

E_{F} ^{2} =OB^{2} +(BC-CD)^{2}

if cosθ = 0.5

E_{F} =\sqrt{(13850*0.5)^{2}+(\frac{3741}{2}-926.2*12.7)^{2}   } =11937.51V

if cosθ= 0.6

EF = 12790.8 V

if cosθ = 0.7

EF = 13731.05 V

if cosθ = 0.8

EF = 14741.6 V

if cosθ = 0.9

EF = 15809.02 V

if cosθ = 1

EF = 13975.6 V

The voltage regulation is

\frac{E_{F}-V_{t}  }{V_{t} } *100

For each value:

if cosθ = 0.5

voltage regulation = -13.8%

if cosθ = 0.6

voltage regulation = -7.6%

if cosθ = 0.7

voltage regulation = -0.85%

if cosθ = 0.8

voltage regulation = 6.4%

if cosθ = 0.9

voltage regulation = 14%

if cosθ = 1

voltage regulation = 0.9%

the graph is shown in the attached image

for 10% of regulation the power factor is 0.81

8 0
3 years ago
Other questions:
  • Which option is a potential environmental risk of adopting a new technology?
    5·1 answer
  • A decorative fountain was built so that water will rise to a hieght of 8 feet above the exit of the pipe. the pipe is 3/4 diamet
    5·1 answer
  • Water discharging into a 10-m-wide rectangular horizontal channel from a sluice gate is observed to have undergone a hydraulic j
    12·1 answer
  • A coal-fired power plant is burning bituminous coal that has an energy content of 12,000 Btu/lb. The power plant is burning the
    13·1 answer
  • Give five examples of
    14·1 answer
  • An engine has a piston with a surface area of 17.31 in2 and can travel 3.44 inches. What is the potential change in volume, disp
    10·1 answer
  • If fog is so bad that I can’t see for short distance what should I do
    9·2 answers
  • 1 A power transmission includes a belt drive, a chain drive and a gear drive. Which of the following is the best arrangement bet
    5·1 answer
  • It tells the amount of materials to be purchased.
    14·1 answer
  • 3.8 LAB - Select lesson schedule with multiple joins
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!