Answer:
The claim is false. ().
Explanation:
The real coefficient of performance of the food freezer is:
The ideal coefficient of performance, that is, when freezer has a reversible process, is:
A real freezer has a coefficient of performance lesser than or equal to ideal coefficient of performance. Since supposed real coefficient of performance is greater than ideal coefficient of performance. The claim is proved to be false.
Answer:
Explanation:
Given V1 = 100m3
P1 = 50bar
P2 = 300bar
T1 = 150°C = 150°C + 273 = 423k
Applying the ideal gas equation ; Pv = mRT
Plugging in the values given to get the mass of the carbon dioxide, the detailed steps and appropriate calculation is as shown in the attached file.
Answer:
<em>Heat is lost at the rate of 750 J/s or W</em>
<em>The thermal resistance is 1 K/W</em>
Explanation:
interior temperature = 900 °C
wall thickness t = 60 cm = 0.6 m
width = 1 m
breadth = 1.5 m
thermal conductivity k = 0.4 W/m-K
outside temperature = 150 °C
heat through the wall = ?
The area of the wall A = w x b = 1 x 1.5 = 1.5 m^2
Temperature difference =
-
= 900 - 150 = 750 °C
note that is also equal to 750 K since to convert from °C to K we'll have to add 273 to both temperature, which will still cancel out when we subtract the two temperatures.
To get the heat that escapes through the wall, we use the equation
Q = Ak
substituting values, we have
Q = 1.5 x 0.4 x = <em>750 J/s or W</em>
Thermal resistance =
= 750/750 =<em> 1 K/W</em>
