1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Airida [17]
3 years ago
11

Explain the effect of heat transfer, reversibilities and irreversibilities on changes in entropy

Engineering
1 answer:
Natali5045456 [20]3 years ago
5 0

Answer is given below

Explanation:

  • The second law of thermodynamics states that in the reversible process, the entropy of the universe is constant, while in the unchanging process, such as the transfer of heat from a hot object to a cold object, the reflection of the universe increases.
  • ΔS = ΔQ ÷ T  
  • The irreversible process increases the entropy of the universe. Since entropy is a state function, the change in entropy of the system is the same, the process is reversible or irreversible. The second law of thermodynamics can be used to determine whether a process is reversible.
  • for an irreversible process, ΔS is not same as reversible process, because more than 1 reversible process is required for 2  ΔS to be equal.
  • if the initial and final states are the same, ΔS for an irreversible process can be calculated as if it were a reversible process.
  • If the initial and final condition is same then ΔS can find out for irreversible process even if it were reversible process

You might be interested in
Steam enters a turbine at 8000 kPa, 440oC. At the exit, the pressure and quality are 150 kPa and 0.19, respectively.
levacccp [35]

Answer:

\dot W_{out} = 3863.98\,kW

Explanation:

The turbine at steady-state is modelled after the First Law of Thermodynamics:

-\dot Q_{out} -\dot W_{out} + \dot m \cdot (h_{in}-h_{out}) = 0

The specific enthalpies at inlet and outlet are, respectively:

Inlet (Superheated Steam)

h_{in} = 3353.1\,\frac{kJ}{kg}

Outlet (Liquid-Vapor Mixture)

h_{out} = 890.1\,\frac{kJ}{kg}

The power produced by the turbine is:

\dot W_{out}=-\dot Q_{out} + \dot m \cdot (h_{in}-h_{out})

\dot W_{out} = -2.93\,kW + (1.57\,\frac{kg}{s} )\cdot (3353.1\,\frac{kJ}{kg} - 890.1\,\frac{kJ}{kg} )

\dot W_{out} = 3863.98\,kW

8 0
3 years ago
(3) Calculate the heat flux through a sheet of brass 7.5 mm (0.30 in.) thick if the temperatures at the two faces are 150°Cand 5
bezimeni [28]

Answer:

a.) 1.453MW/m2,  b.)  2,477,933.33 BTU/hr  c.) 22,733.33 BTU/hr  d.) 1,238,966.67 BTU/hr

Explanation:

Heat flux is the rate at which thermal (heat) energy is transferred per unit surface area. It is measured in W/m2

Heat transfer(loss or gain) is unit of energy per unit time. It is measured in W or BTU/hr

1W = 3.41 BTU/hr

Given parameters:

thickness, t = 7.5mm = 7.5/1000 = 0.0075m

Temperatures 150 C = 150 + 273 = 423 K

                        50 C = 50 + 273 = 323 K

Temperature difference, T = 423 - 323 = 100 K

We are assuming steady heat flow;

a.) Heat flux, Q" = kT/t

K= thermal conductivity of the material

The thermal conductivity of brass, k = 109.0 W/m.K

Heat flux, Q" = \frac{109 * 100}{0.0075} = 1,453,333.33 W/m^{2} \\ Heat flux, Q" = 1.453MW/m^{2} \\

b.) Area of sheet, A = 0.5m2

Heat loss, Q = kAT/t

Heat loss, Q = \frac{109*0.5*100}{0.0075} = 726,666.667W

Heat loss, Q = 726,666.667 * 3.41 = 2,477,933.33 BTU/hr

c.) Material is now given as soda lime glass.

Thermal conductivity of soda lime glass, k is approximately 1W/m.K

Heat loss, Q=\frac{1*0.5*100}{0.0075} = 6,666.67W

Heat loss, Q = 6,666.67 * 3.41 = 22,733.33 BTU/hr

d.) Thickness, t is given as 15mm = 15/1000 = 0.015m

Heat loss, Q=\frac{109*0.5*100}{0.015} =363,333.33W

Heat loss, Q = 363,333.33 * 3.41 = 1,238,966.67 BTU/hr

5 0
2 years ago
Technician A says it will save you money if you get a high interest rate from a bank on the loan. Technician B says it is always
zubka84 [21]
Is there a other option
5 0
3 years ago
What is JIT and why would you advocate it to reduce inventory?
bazaltina [42]

Explanation:

Just in time inventory is a system of managing inventory. It is a method to reduce waste, lower cost and increase profit. According to it the raw material orders are directly aligned with the production schedules. In simple words every component of a unit is arriving just in time to be used.

So JIT would be advocated to reduce inventory.

7 0
2 years ago
Most ceilings are covered with plaster or…
Monica [59]

Explanation:

Most ceilings are coverd with plaster or board.

8 0
3 years ago
Read 2 more answers
Other questions:
  • A dipstick is (a direct,an indirect) measurement device
    13·1 answer
  • Your Java program will be reading input from a file name strInput.txt. Each record contains String firstname String lastName Str
    13·1 answer
  • Make sure that the switch is on (if the drill is electric), the chuck key is not removed before you plug in the drill or turn it
    11·2 answers
  • What is differences Between hard shoulder & soft shoulder in civil Engineerin?
    9·1 answer
  • In part A you are asked to write the pseudocode for the program. In part B you are asked to write the syntax of the code for the
    11·1 answer
  • The following sentence can be categorized as what stage in the Scientific Method: Abraham notices that Saharan desert ants will
    6·1 answer
  • ____________ is the organization that oversees environmental compliance.
    14·1 answer
  • calculate force and moment reactions at bolted base O of overhead traffic signal assembly. each traffic signal has a mass 36kg,
    6·1 answer
  • Hey any one ride dirtbikes here
    5·2 answers
  • In-------process the hot drawn bar or rod is pulled through the die.
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!