A water tank filled with solar-heated water at 40°C is to be used for showers in a field using gravity-driven flow.
1 answer:
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Answer:
Option ‘a’ is the cheapest for this house.
Explanation:
Cheapest method of heating must have least cost per kj of energy. So, convert all the energy in the same unit (say kj) and take select the cheapest method to heat the house.
Given:
Three methods are given to heat a particular house are as follows:
Method (a)
Through Gas, this gives energy of amount $1.33/therm.
Method (b)
Through electric resistance, this gives energy of amount $0.12/KWh.
Method (c)
Through oil, this gives energy of amount $2.30/gallon.
Calculation:
Step1
Change therm to kj in method ‘a’ as follows:
$/kj.
Step2
Change kWh to kj in method ‘b’ as follows:
$/kj.
Step3
Change kWh to kj in method ‘c’ as follows:
$/kj.
Thus, the method ‘a’ has least cost as compare to method b and c.
So, option ‘a’ is the cheapest for this house.
Answer:
1.
2.
Explanation:
1.
Given:
- height of the window pane,
- width of the window pane,
- thickness of the pane,
- thermal conductivity of the glass pane,
- temperature of the inner surface,
- temperature of the outer surface,
<u>According to the Fourier's law the rate of heat transfer is given as:</u>
here:
A = area through which the heat transfer occurs =
dT = temperature difference across the thickness of the surface =
dx = t = thickness normal to the surface =
2.
- air spacing between two glass panes,
- area of each glass pane,
- thermal conductivity of air,
- temperature difference between the surfaces,
<u>Assuming layered transfer of heat through the air and the air between the glasses is always still:</u>
Answer:
a = 1.68m/
Explanation:
Please kindly find the attached file for explanations
