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
Luda [366]
2 years ago
15

An air standard cycle with constant specific heats is executed in a closed system with 0.003 kg of air and consists of the follo

wing three processes:
1-2 - V= Constant heat addition from 95 kPa and 17 Deg Celcius to 380 kPa
2-3 - Isentropic expansion to 95 kPa
3-1 - P= Constant heat rejection to initial state

a) Show cycle on P-v and T-s diagrams
b) Calculate net work per cycle in kJ
c) Determine thermal efficiency

Engineering
1 answer:
Vsevolod [243]2 years ago
7 0

Answer:

a) Please see attached copy below

b) 0.39KJ

c)  20.9‰

Explanation:

The three process of an air-standard cycle are described.

Assumptions

1. The air-standard assumptions are applicable.

2. Kinetic and potential energy negligible.

3. Air in an ideal gas with a constant specific heats.

Properties:

The properties of air are gotten from the steam table.

b) T₁=290K ⇒ u₁=206.91 kj/kg, h₁=290.16 kj/kg.

P₂V₂/T₂=P₁V₁/T₁⇒ T₂=P₂T₁/P₁ = 380/95(290K)= 1160K

T₃=T₂(P₃/P₂)⁽k₋1⁾/k =(1160K)(95/380)⁽⁰°⁴/₁.₄⁾ =780.6K

Qin=m(u₂₋u₁)=mCv(T₂-T₁)

=0.003kg×(0.718kj/kg.k)(1160-290)K= 1.87KJ

Qout=m(h₃₋h₁)=mCp(T₃₋T₁)

=0.003KG×(1.005kj/kg.k(780.6-290)K= 1.48KJ

Wnet, out= Qin-Qout = (1.87-1.48)KJ =0.39KJ

c)ηth= Wnet/W₍in₎ =0.39KJ/1.87KJ = 20.9‰

You might be interested in
Block A has a weight of 8 lb. and block B has a weight of 6 lb. They rest on a surface for which the coefficient of kinetic fric
kkurt [141]

Answer:

For block A, a = 9.66 ft/s²

For block B, a = 15 ft/s²

Explanation:

A free body diagram for this force system is attached to this solution

Mass of block A = m₁ = 8 lb

Mass of block B = m₂ = 6 lb

Coefficient of kinetic friction = μ

Normal reaction on the blocks = N

Spring stiffness of the spring btw block A and B = k = 20 lb/ft

Compression of the spring = 0.2 ft

Analysing Block A first

The forces on block A include, the weight, normal reaction, frictional force and the elastic force due to the spring

Sum of forces in the y-direction = 0

So, the weight of the block = Normal reaction of the surface on the block

N = W = 8 lb

Sum of forces in the x-direction = maₓ

(k × x) - (μ × N) = maₓ

m = W/g = 8/32.2 = 0.248 lbm

(20×0.2) - (0.2 × 8) = (0.248) aₓ

aₓ = 9.66 ft/s²

The forces on block B include, the weight, normal reaction, frictional force and the elastic force due to the spring

Sum of forces in the y-direction = 0

So, the weight of the block = Normal reaction of the surface on the block

N = W = 6 lb

Sum of forces in the x-direction = maₓ

(k × x) - (μ × N) = maₓ

m = W/g = 6/32.2 = 0.186 lbm

(20×0.2) - (0.2 × 6) = (0.186) aₓ

aₓ = 15 ft/s²

4 0
3 years ago
A composite wall is composed of 20 cm of concrete block with k = 0.5 W/m-K and 5 cm of foam insulation with k = 0.03 W/m-K. The
wariber [46]

Answer:

4.8°C

Explanation:

The rate of heat transfer through the wall is given by:

q=\frac{Ak}{L}dT

\frac{q}{A}=\frac{k}{L}dT

Assumptions:

1) the system is at equilibrium

2) the heat transfer from foam side to interface and interface to block side is equal. There is no heat retention at any point

3) the external surface of the wall (concrete block side) is large enough that all heat is dissipated and there is no increase in temperature of the air on that side

{k_{fi}= 0.03 W/m.K

{L_{fi}= 5 cm = 0.05 m

{T_{fi}= 25 \°C

{k_{cb} = 0.5 W/m.K

{L_{cb}= 20 cm = 0.20 m

{T_{cb}= 0 \°C

{T_{m}= ? \°C = temperature at the interface

Solving for {T_{m} will give the temperature at the interface:

\frac{q}{A}=\frac{k_{fi} }{L_{fi} }(T_{fi} -T_{m})=\frac{k_{cb} }{L_{cb} }(T_{m} -T_{cb})

\frac{0.03}{0.05 }(25 -T_{m})=\frac{0.5}{0.2}(T_{m} -0})

15 -0.6T_{m}=2.5T_{m}

3.1T_{m}=15

T_{m}=4.8

3 0
3 years ago
Why not just put all the set up steps within each step? it is because we want to keep our code __ ? (3 letters)
andrezito [222]

Why not simply include each step's setup instructions within it? is it due to our desire to maintain DRY (Don't Repeat Yourself) code?

<h3>What is the purpose of unit testing?</h3>

Program testing is known as "unit testing" involves testing individual software components. When developing an application, unit testing is done on the software product. An individual component could be a technique or a specific function.

Unit testing's primary goal is to separate written code for testing to see if it functions as intended. Unit testing is a crucial stage in the development process because, when done properly, it can aid in finding early code issues that could be more challenging to identify in subsequent testing phases.

The core of the testing process consists of unit testing and functional testing. The primary distinction between the two is that during the development cycle, the developer conducts unit testing. The tester does functional testing at the system testing level.

To learn more about unit testing refers to:

brainly.com/question/22900395

#SPJ4

8 0
1 year ago
When you see a street with white markings only, what kind of street is it?
Georgia [21]

Answer:

it's a one way street

3 0
3 years ago
A homeowner consumes 260 kWh of energy in July when the family is on vacation most of the time. Determine the average cost per k
Llana [10]

Answer:

16.2 cents

Explanation:

Given that a homeowner consumes 260 kWh of energy in July when the family is on vacation most of the time.

Where Base monthly charge of $10.00. First 100 kWh per month at 16 cents/kWh. Next 200 kWh per month at 10 cents/kWh. Over 300 kWh per month at 6 cents/kWh.

For the first 100 kWh:

16 cent × 100 = 1600 cents = 16 dollars

Since 1 dollar = 100 cents

For the remaining energy:

260 - 100 = 160 kwh

10 cents × 160 = 1600 cents = 16 dollars

The total cost = 10 + 16 + 16 = 42 dollars

Note that the base monthly of 10 dollars is added.

The cost of 260 kWh of energy consumption in July is 42 dollars

To determine the average cost per kWh for the month of July, divide the total cost by the total energy consumed.

That is, 42 / 260 = 0.1615 dollars

Convert it to cents by multiplying the result by 100.

0.1615 × 100 = 16.15 cents

Approximately 16.2 cents

7 0
3 years ago
Other questions:
  • According to Manor, the example of the subway train in New York City is an example of which type of uniqueness?
    9·1 answer
  • Water flovs in a pipe of diameter 150 mm. The velocity of the water is measured at a certain spot which reflects the average flo
    13·1 answer
  • Create a function (prob3_5) that will take inputs of vectors x and y in feet, scalar N, scalars L and W in feet and scalars T1 a
    6·1 answer
  • Basic output with variables (Java) This zyLab activity is intended for students to prepare for a larger programming assignment.
    7·1 answer
  • A hot-water stream at 80°C enters a mixing chamber with a mass flow rate of 0.46 kg/s where it is mixed with a stream of cold wa
    14·1 answer
  • In a diesel engine, the fuel is ignited by (a) spark (c) heat resulting from compressing air that is supplied for combustion (d)
    14·1 answer
  • A tank has two rooms separated by a membrane. Room A has 1 kg of air and a volume of 0.5 m3; room B has 0.75 m3 of air with dens
    15·1 answer
  • 6.3.3 Marks on an exam in a statistics course are assumed to be normally distributed
    14·1 answer
  • Using your knowledge of how an ATM is used, develop a set of use cases that could serve as a basis for understanding the require
    15·1 answer
  • Explain how to properly engage the safety latches on the Stan Design Pit Jack.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!