Answer:
The cost and size of materials needed to produce energy
Explanation:
Artificial photosynthesis is a chemical process that uses solar cells instead of chlorophyll to absorb sunlight and convert it into electricity. This process uses artificial leaves that require man-made catalyst to spilt water present in the air into hydrogen and oxygen. It is clear that the reaction requires heat from the sun for energy production thus the technology is expensive to be applied in most areas of the world. Additionally, results obtained from previous undertaken projects of this type has been ineffective and unsustainable because it involves a lot of trial and error.
Answer:
|W|=169.28 KJ/kg
ΔS = -0.544 KJ/Kg.K
Explanation:
Given that
T= 100°F
We know that
1 °F = 255.92 K
100°F = 310 .92 K

We know that work for isothermal process

Lets take mass is 1 kg.
So work per unit mass

We know that for air R=0.287KJ/kg.K


W= - 169.28 KJ/kg
Negative sign indicates compression
|W|=169.28 KJ/kg
We know that change in entropy at constant volume


ΔS = -0.544 KJ/Kg.K
Answer:
Explanation:
They are altered by variables such as temperature hence making materials challenging when dealing with them.
Answer:
t = 2244.3 sec
Explanation:
calculate the thermal diffusivity


Temperature at 28 mm distance after t time = = 50 degree C
we know that

![\frac{ 50 -25}{300-25} = erf [\frac{28\times 10^{-3}}{2\sqrt{1.34\times 10^{-5}\times t}}]](https://tex.z-dn.net/?f=%5Cfrac%7B%2050%20-25%7D%7B300-25%7D%20%3D%20erf%20%5B%5Cfrac%7B28%5Ctimes%2010%5E%7B-3%7D%7D%7B2%5Csqrt%7B1.34%5Ctimes%2010%5E%7B-5%7D%5Ctimes%20t%7D%7D%5D)

from gaussian error function table , similarity variable w calculated as
erf w = 0.909
it is lie between erf w = 0.9008 and erf w = 0.11246 so by interpolation we have
w = 0.08073
![erf 0.08073 = erf[\frac{3.8245}{\sqrt{t}}]](https://tex.z-dn.net/?f=erf%200.08073%20%3D%20erf%5B%5Cfrac%7B3.8245%7D%7B%5Csqrt%7Bt%7D%7D%5D)

solving fot t we get
t = 2244.3 sec