Answer:
a)
, b)
, c)
, d)
, e) 
Explanation:
a) The coefficient of performance of the reversible refrigeration cycle is:


The temperature of the hot reservoir is:



b) The coefficient of performance is:


c) The temperature of the hot reservoir can be determined with the help of the following relation:






d) The coefficient of performance is:


e) The temperature of the cold reservoir is:




Answer:
COP = 0.090
Explanation:
The general formula for COP is:
COP = Desired Output/Required Input
Here,
Desired Output = Heat removed from water while cooling
Desired Output = (Specific Heat of Water)(Mass of Water)(Change in Temperature)/Time
Desired Output = [(4180 J/kg.k)(3.1 kg)(25 - 11)k]/[(12 hr)(3600 sec/hr)]
Desired Output = 4.199 W
And the required input can be given as electrical power:
Required Input = Electrical Power = (Current)(Voltage)
Required Input = (2.9 A)(16 V) = 46.4 W
Therefore:
COP = 4.199 W/46.4 W
<u>COP = 0.090</u>
In this question, we are missing some of the information that is necessary in order to answer this question properly. However, we can look at what a relational database is in order to help you answer the question on your own.
A relational database is a set of tables from which data can be accessed. This can take place even without the need to reorganize the database tables. The programming interface of a relational database is the Structured Query Language (SQL). This approach was invented by E. F. Codd, who came up with it in 1970 while he was a programmer at IBM.
Answer:
Explanation:
a. Cast iron or Aluminium alloy are typically used. Aluminium is much lighter in weight and it can transfer heat better to the coolant. While Cast Iron is typically stronger and is thus still used by the manufacturers.
b. Copper can be used as a condensing heat exchanger for hot steam due to its optimal thermal properties and its ability to resist corrosion.
c. high-speed steel are perfect for producing drill bits because of its hardness and resistance to heat to an extent. Drill bits tend to produce heat as a result of the friction between it and the material to be drilled.
d. lead can be used as a container for strong acids because of its anti-corrosive properties
e.zinc and copper can be used as fuel in pyrotechnics mainly due to the fact that burn with refreshing colours. Aluminium can also be used.
f. Platinum is the metal that best suits this purpose because of its high melting point and resistivity to oxidation.
Answer:
a. 318.2k
b. 45.2kj
Explanation:
Heat transfer rate to an object is equal to the thermal conductivity of the material the object is made from, multiplied by the surface area in contact, multiplied by the difference in temperature between the two objects, divided by the thickness of the material.
See attachment for detailed analysis