Answer:
0.5 kW
Explanation:
The given parameters are;
Volume of tank = 1 m³
Pressure of air entering tank = 1 bar
Temperature of air = 27°C = 300.15 K
Temperature after heating = 477 °C = 750.15 K
V₂ = 1 m³
P₁V₁/T₁ = P₂V₂/T₂
P₁ = P₂
V₁ = T₁×V₂/T₂ = 300.15 * 1 /750.15 = 0.4 m³
For ideal gas, 
= 5/2×R = 5/2*0.287 = 0.7175 kJ
PV = NKT
N = PV/(KT) = 100000×1/(750.15×1.38×10⁻²³)
N = 9.66×10²⁴
Number of moles of air = 9.66×10²⁴/(6.02×10²³) = 16.05 moles
The average mass of one mole of air = 28.8 g
Therefore, the total mass = 28.8*16.05 = 462.135 g = 0.46 kg
∴ dQ = 0.46*0.7175*(750.15 - 300.15) = 149.211 kJ
The power input required = The rate of heat transfer = 149.211/(60*5)
The power input required = 0.49737 kW ≈ 0.5 kW.
Answer:
Minimum electrical power required = 3.784 Watts
Minimum battery size needed = 3.03 Amp-hr
Explanation:
Temperature of the beverages, 
Outside temperature, 
rate of insulation, 
To get the minimum electrical power required, use the relation below:
V = 5 V
Power = IV
If the cooler is supposed to work for 4 hours, t = 4 hours
Minimum battery size needed = 3.03 Amp-hr
ANSWERS:
Explanation:
Given:
Piston cylinder assembly which mean that the process is constant pressure process P=C.
<u>AMMONIA </u>
state(1)
saturated vapor 
The temperature 
Isothermal process 
a)
( double)
b)
(reduced by half)
To find the final state by giving the quality in lbf/in we assume the friction is neglected and the system is in equilibrium.
state(1)
using PVT data for saturated ammonia
then the state exists in the supper heated region.
a) from standard data
assume linear interpolation
b)
from standard data
then the state exist in the wet zone
Explanation:
volume = πR²h/3
= πx35²x50/3
= 192325/3
= 64166.725
number of layers n = 50mm/0.05
n = 1000layers
average volume = 64166.725/1000
= 64.167mm³
average area = 64.167/0.05
= 1283.34mm²
average time = 1283.34/900mm x 0.22
= 6.48
6.48 + 15 seconds
= 21.48 seconds
time required = 1000x21.48
= 21480 seconds
convert to minutes
21480/60
= 358 minutes
21480/3600
= 5.967 hours
