Answer:
a) What is the surface temperature, in °C, after 400 s?
T (0,400 sec) = 800°C
b) Yes, the surface temperature is greater than the ignition temperature of oak (400°C) after 400 s
c) What is the temperature, in °C, 1 mm from the surface after 400 s?
T (1 mm, 400 sec) = 798.35°C
Explanation:
oak initial Temperature = 25°C = 298 K
oak exposed to gas of temp = 800°C = 1073 K
h = 20 W/m².K
From the book, Oak properties are e=545kg/m³ k=0.19w/m.k Cp=2385J/kg.k
Assume: Volume = 1 m³, and from energy balance the heat transfer is an unsteady state.
From energy balance: ![\frac{T - T_{\infty}}{T_i - T_{\infty}} = Exp (\frac{-hA}{evCp})t](https://tex.z-dn.net/?f=%5Cfrac%7BT%20-%20T_%7B%5Cinfty%7D%7D%7BT_i%20-%20T_%7B%5Cinfty%7D%7D%20%3D%20Exp%20%28%5Cfrac%7B-hA%7D%7BevCp%7D%29t)
Initial temperature wall = ![T_i](https://tex.z-dn.net/?f=T_i)
Surface temperature = T
Gas exposed temperature = ![T_{\infty}](https://tex.z-dn.net/?f=T_%7B%5Cinfty%7D)
I believe the answer is D: brazing
Hope this helps you have a good night
It is accurate to say that site engineering does not require particular consideration for soils with low percolation rates.
<h3>What are percolation rates?</h3>
- The rate at which water percolates through the soil is a measure of its ability to absorb and treat effluent, or wastewater that has undergone preliminary treatment in a septic tank.
- Minutes per inch are used to measure percolation rate (mpi).
- The process of a liquid gently moving through a filter is called percolation. This is how coffee is typically brewed.
- The Latin verb percolare, which meaning "to strain through," is the source of the word "percolation." When liquid is strained through a filter, such as when making coffee, percolation occurs.
To learn more about percolation rates, refer to:
brainly.com/question/28170860
#SPJ4
Answer:
Magnitude of velocity=10.67 m/s
Magnitude of acceleration=24.62 ft/![s^{2}](https://tex.z-dn.net/?f=s%5E%7B2%7D)
Explanation:
The solution of the problem is given in the attachments