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
EastWind [94]
3 years ago
10

In a home, air infiltrates from the outside through cracks around doors and windows. Consider a residence where the total length

of cracks is 62 m and the total internal volume is 210 m3 . Due to the wind, 9.4 x 10-5 kg/s of air enters per meter of crack and exits up a chimney. Assume air temperature is the same inside and out and air density is constant at 1.186 kg/m3 . If windows and doors are not opened or closed, estimate the time required for one complete air change in the building.
Engineering
1 answer:
masya89 [10]3 years ago
3 0

Answer:

Time period  = 41654.08 s

Explanation:

Given data:

Internal volume is 210 m^3

Rate of air infiltration  9.4 \times 10^{-5} kg/s

length of cracks 62 m

air density = 1.186 kg/m^3

Total rate of air infiltration = 9.4\times 10^{-5} \times 62 = 582.8\times 10{-5} kg/s

total volume of air  infiltration= \frac{582.8\times 10{-5}}{1.156} = 5.04\times 10^{-3} m^3/s

Time period = \frac{210}{5.04\times 10^{-3}} = 41654.08 s

You might be interested in
Some of our modern kitchen cookware is made of ceramic materials. (a) List at least three important characteristics required of
Alisiya [41]

Answer:

A)

It should be Non- toxic

It should possess high Thermal conductivity

It should have the Required Thermal diffusivity

B)

  • stoneware : This material has good thermal diffusivity and it  is quite affordable and it is used in making pizza stones
  • porcelain: mostly used for mugs and it is non-toxic
  • Pyrex : posses good thermal conductivity used in oven

C)   All the materials are suitable because they serve different purposes when making modern kitchen cookware

Explanation:

A) characteristics required of a ceramic material to be used as a kitchen cookware

  • It should be Non- toxic
  • It should possess high Thermal conductivity
  • It should have the Required Thermal diffusivity

B) comparison of three ceramic materials as to their relative properties

  • stoneware : This material has good thermal diffusivity and it  is quite affordable and it is used in making pizza stones
  • porcelain: mostly used for mugs and it is non-toxic
  • Pyrex : posses good thermal conductivity used in ovens

C) material most suitable for the cookware.

 All the materials are suitable because they serve different purposes when making modern kitchen cookware

8 0
2 years ago
A light bulb is switched on and within a few minutes its temperature becomes constant. Is it at equilibrium or steady state.
EleoNora [17]

Answer:

The temperature attains equilibrium with the surroundings.  

Explanation:

When the light bulb is lighted we know that it's temperature will go on increasing as the filament of the bulb has to  constantly dissipates energy during the time in which it is on. Now this energy is dissipated as heat as we know it, this heat energy is absorbed by the material of the bulb which is usually made up of glass, increasing it's temperature. Now we know that any object with temperature above absolute zero has to dissipate energy in form of radiations.

Thus we conclude that the bulb absorbs as well as dissipates it's absorbed thermal energy. we know that this rate is dependent on the temperature of the bulb thus it the temperature of the bulb does not change we can infer that an equilibrium has been reached in the above 2 processes i.e the rate of energy absorption equals the rate of energy dissipation.

Steady state is the condition when the condition does not change with time no matter whatever the surrounding conditions are.

6 0
3 years ago
O que é necessário se conhecer para a determinação de uma força concentrada em um ponto?
skelet666 [1.2K]

Answer: its c

Explanation:

7 0
3 years ago
If i see i dead army person will i be asked questions and if i see the person who did it
True [87]

Answer:

Yes we take dead army people like it was on purspose because people would like to kill us off but yes you would be asked Questions and we would ask you if you saw any suspects

5 0
3 years ago
Read 2 more answers
A NC drill press is to perform a series of through-hole drilling operations on a 1.75 in thick aluminum plate that is a componen
jekas [21]

Answer:

26.7 min

Explanation:

First, we will find the <u>time required to drill each hole</u>:

  • N = 300 x 12/0.75 \pi = 1527.7 rev/min
  • fr = 1527.7 (0.015) = 22.916 in/min

Formula for <u>distance per hole</u>: 0.5 + A + 1.75

  • A = 0.5 (0.75) tan (90-100 / 2) = 0.315 in
  • Tm = (0.5 + 0.315 + 1.75) / 22.916 = 0.112 min

Now, we will calculate the <u>time required to draw back the drill form hole</u>:

              = 0.112 / 2 = 0.056 min

Time to move between holes = 1.5 / 15 = 0.1 min

For 100 holes, the number of moves between holes = 99

Total time required to drill 100 holes (t):

                       t = 100 (0.112 + 0.056) + 99 (0.1) = 26.7 min

7 0
3 years ago
Read 2 more answers
Other questions:
  • The wet density of a sand was found to be 1.9 Mg/m3 and the field water content was 10%. In the laboratory, the density of solid
    9·1 answer
  • If the bar assembly is made of a material having a yield stress of σY = 45 ksi , determine the minimum required dimensions h1 an
    7·1 answer
  • . A 10W light bulb connected to a series of batteries may produce a brighter lightthan a 250W light bulb connected to the same b
    8·2 answers
  • An organization is struggling to differentiate threats from normal traffic and access to systems. A security engineer has been a
    12·1 answer
  • Perform a theoretical analysis of the rectangular profiled cantilevered beam. Provide a theoretical expression (in symbolic form
    14·1 answer
  • A closed, rigid tank fitted with a paddle wheel contains 2.0 kg of air, initially at 200oC, 1 bar. During an interval of 10 minu
    8·1 answer
  • Glyphicons is mainly used for​
    12·1 answer
  • How would you design a wheelchair for wheelchair-using basketball players? Would you make it more or less massive?
    11·1 answer
  • HOLA COMO ESTAN TODOS
    14·1 answer
  • 15- Vipsana's Gyros House sells gyros. The cost of ingredients (pita, meat, spices, etc.) to make a gyro is $2.00. Vipsana pays
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!