The Stefan-Boltzmann law can be employed to estimate the rate of radiation of energy H from a surface, as in
1 answer:
Explanation:
A.
H = Aeσ^4
Using the stefan Boltzmann law
When we differentiate
dH/dT = 4AeσT³
dH/dT = 4(0.15)(0.9)(5.67)(10^-8)(650)³
= 8.4085
Exact error = 8.4085x20
= 168.17
H(650) = 0.15(0.9)(5.67)(10^-8)(650)⁴
= 1366.376watts
B.
Verifying values
H(T+ΔT) = 0.15(0.9)(5.67)(10)^-8(670)⁴
= 1542.468
H(T+ΔT) = 0.15(0.9)(5.67)(10^-8)(630)⁴
= 1205.8104
Error = 1542.468-1205.8104/2
= 168.329
ΔT = 40
H(T+ΔT) = 0.15(0.9)(5.67)(10)^-8(690)⁴
= 1735.05
H(T-ΔT) = 0.15(0.9)(5.67)(10^-8)(610)⁴
= 1735.05-1059.83/2
= 675.22/2
= 337.61
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Answer:
Q = -68.859 kJ
Explanation:
given details
mass
initial pressure P_1 = 104 kPa
Temperature T_1 = 25 Degree C = 25+ 273 K = 298 K
final pressure P_2 = 1068 kPa
Temperature T_2 = 311 Degree C = 311+ 273 K = 584 K
we know that
molecular mass of
R = 8.314/44 = 0.189 kJ/kg K
c_v = 0.657 kJ/kgK
from ideal gas equation
PV =mRT
WORK DONE
w = 586*(0.1033 -0.514)
W =256.76 kJ
INTERNAL ENERGY IS
HEAT TRANSFER
= 187.902 +(-256.46)
Q = -68.859 kJ
Answer:
The corresponding absolute pressure of the boiler is 24.696 pounds per square inch.
Explanation:
From Fluid Mechanics, we remember that absolute pressure (), measured in pounds per square inch, is the sum of the atmospheric pressure and the working pressure (gauge pressure). That is:
(1)
Where:
- Atmospheric pressure, measured in pounds per square inch.
- Working pressured of the boiler (gauge pressure), measured in pounds per square inch.
If we suppose that and
, then the absolute pressure is:
The corresponding absolute pressure of the boiler is 24.696 pounds per square inch.