The complete Question is:
Airflow through a long, 0.15-m-square air conditioning duct maintains the outer duct surface temperature at 10°C. If the horizontal duct is uninsulated and exposed to air at 35°C in the crawlspace beneath a home, what is the heat gain per unit length of the duct? Evaluate the properties of air at 300 K. For the sides of the duct, use the more accurate Churchill and Chu correlations for laminar flow on vertical plates.
What is the Rayleigh number for free convection on the outer sides of the duct?
What is the free convection heat transfer coefficient on the outer sides of the duct, in W/m2·K?
What is the Rayleigh number for free convection on the top of the duct?
What is the free convection heat transfer coefficient on the top of the duct, in W/m2·K?
What is the free convection heat transfer coefficient on the bottom of the duct, in W/m2·K?
What is the total heat gain to the duct per unit length, in W/m?
Answers:
- 7709251 or 7.709 ×10⁶
- 4.87
- 965073
- 5.931 W/m² K
- 2.868 W/m² K
- 69.498 W/m
Explanation:
Find the given attachments for complete explanation
Answer:
SEE EXPLANATION
Explanation:
## This is a more, "whats your opinion question" so answers may vary from person to person
The industrial revolution created many jobs, boosted the economy, but created many issues too. Including but not limited too, child labor, decrease in workplace saftey for the sake of profits, hard hours, and many injuries and deaths (i.e. Triangle Shirtwaist Factory Fire). In the short term, companies used the oppertunity of little workers rights to exploit them for profits, yet in the long term boomed the economy and our exports and America's indepence from buying imports.
Answer:
True
Explanation:
Wastewater should never be discharged into storm sewers. Storm sewers are constructed to store rainwater.
Rainwater passes through storm sewers to the nearest underground water resource if the wastewater discharge into storm sewers, then they will also pollute the ground water, so usually the dirty water is not put in the storm sewers.
Answer:
fracture will occur as the value is less than E/10 (= 22.5)
Explanation:
If the maximum strength at tip Is greater than theoretical fracture strength value then fracture will occur and if the maximum strength is lower than theoretical fracture strength then no fracture will occur.
![\sigma_m = 2\sigma_o [\frac{a}{\rho_t}]^{1/2}](https://tex.z-dn.net/?f=%5Csigma_m%20%3D%202%5Csigma_o%20%5B%5Cfrac%7Ba%7D%7B%5Crho_t%7D%5D%5E%7B1%2F2%7D)
![= 2\times 750 (\frac{\frac{0.2mm}{2}}{0.001 mm}})^{1/2}](https://tex.z-dn.net/?f=%3D%20%202%5Ctimes%20750%20%28%5Cfrac%7B%5Cfrac%7B0.2mm%7D%7B2%7D%7D%7B0.001%20mm%7D%7D%29%5E%7B1%2F2%7D)
= 15 GPa
fracture will occur as the value is less than E/10 = 22.5