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3 years ago

15

Consider a complete cycle, such as a power cycle which starts at state 1, undergoes several steps, and returns to state 1. What

is the net change in energy?

1 answer:

xxTIMURxx [149]3 years ago

6 0

Answer:

Explained

Explanation:

Since, the cycle is complete and the working fluid reaches the same state after the process where it was before the process so net change in internal energy and Enthalpy is zero since these two are point functions and does not depend upon the path taken to reach the state point. In power producing cycle the net interaction is equal to net work interaction that is heat is converted to work.

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The pressure and temperature at the beginning of compression of a cold air-standard Diesel cycle are 100 kPa and 300K, respectiv

hram777 [196]

Answer:

Cut off ratio=2.38

Explanation:

Given that

$T_1=300K$

$P_1=100KPa$

$P_2=P_3=7200KPa$

$T_3=2250K$

Lets take $T_1$ is the temperature at the end of compression process

For air γ=1.4

$\dfrac{T_2}{T_1}=\left(\dfrac{P_2}{P_1}\right)^{\dfrac{\gamma -1}{\gamma}}$

$\dfrac{T_2}{300}=\left(\dfrac{7200}{100}\right)^{\dfrac{1.4-1}{1.4}}$

$T_2=1070K$

At constant pressure

$\dfrac{T_3}{T_2}=\dfrac{V_3}{V_2}$

$\dfrac{2550}{1070}=\dfrac{V_3}{V_2}$

$\dfrac{V_3}{V_2}=2.83$

So cut off ratio

$cut\ off\ ratio =\dfrac{V_3}{V_2}$

Cut off ratio=2.38

6 0

4 years ago

For a bolted assembly with eight bolts, the stiffness of each bolt is kb = 1.0 MN/mm and the stiffness of the members is km = 2.

rjkz [21]

Answer:

a) 0.978

b) 0.9191

c) 1.056

d) 0.849

Explanation:

Given data :

Stiffness of each bolt = 1.0 MN/mm

Stiffness of the members = 2.6 MN/mm per bolt

Bolts are preloaded to 75% of proof strength

The bolts are M6 × 1 class 5.8 with rolled threads

Pmax =60 kN, Pmin = 20kN

<u>a) Determine the yielding factor of safety</u>

$n_{p} = \frac{S_{p}A_{t} }{CP_{max}+ F_{i} }$ ------ ( 1 )

Sp = 380 MPa, At = 20.1 mm^2, C = 0.277, Pmax = 7500 N, Fi = 5728.5 N

Input the given values into the equation above

equation 1 becomes ( np ) = $\frac{380*20.1}{0.277*7500*5728.5}$ = 0.978

note : values above are derived values whose solution are not basically part of the required solution hence they are not included

<u>b) Determine the overload factor of safety</u>

$n_{L} = \frac{S_{p}A_{t}-F_{i} }{C(P_{max} )}$ ------- ( 2 )

Sp = 380 MPa, At = 20.1 mm^2, C = 0.277, Pmax = 7500 N, Fi = 5728.5 N

input values into equation 2 above

hence : $n_{L}$ = 0.9191 $n_{L} = 0.9191$

<u>C) Determine the factor of safety based on joint separation</u>

$n_{0} = \frac{F_{i} }{P_{max}(1 - C ) }$

Fi = 5728.5 N, Pmax = 7500 N, C = 0.277,

input values into equation above

Hence $n_{0}$ = 1.056

<u>D) Determine the fatigue factor of safety using the Goodman criterion.</u>

nf = 0.849

attached below is the detailed solution .

4 0

3 years ago

Identify the careers that match the descriptions. Operates machines that cut through rocks underground so natural resources can

attashe74 [19]

Answer:

1. Operates machines that cut through rocks underground so natural resources can be harvested: Mine-cutting and channeling operator

2. Studies and manages natural resources to protect the environment: Conservation Scientist

3. Manages forests for conservation, human enjoyment, and harvesting: Forster

4. Inspects, measures, and classifies logs based on quality: Log grader or scaler

5. Operates machinery to cut down trees and move logs: Logging equipment Operator

Explanation:

Conservation Scientist – studies and manages natural resources to protect the environment and support human uses of natural resources

Forester – manages forests for conservation, human enjoyment, and tree harvesting

Mine Cutting and Channeling Machine Operator – operates machinery in underground mines that bring natural resources up to the surface for human use

Logging Equipment Operator – operates logging machinery, such as tractors or bulldozers

Log Grader or Scaler – inspects, measures, and classifies logs based on their quality

4 0

4 years ago

Read 2 more answers

Tech A says that horsepower is a measurement simply of the amount of work being performed. Tech B says that horsepower can be ca

snow_tiger [21]

Answer:

Tech B

Explanation:

Horsepower (hp) refers to a unit of measurement of power in respect of the output of engines or motors.

Horsepower is the common unit of power. It indicates the rate at which work is done.

The formula $\frac{rpm*T}{5252}$ , where rpm is the engine speed, T is the torque, and 5,252 is radians per second.

So,

Tech B is correct

6 0

3 years ago

Which of the following is true Select one: a. HTML stands for Hyper Text Markup Language is a language for describing web pages

Free_Kalibri [48]

Answer:

The answer to the above question is option C (HTML stands for Hyper Text Markup Language is a language for describing web pages and not a programming language).

Explanation:

HTML stands for Hypertext Markup Language.

HTML is a web language that allows users to create and structure sections, paragraphs, headings, links, and block quotes to define the structure of web pages by using various tags.

HTML describes the structure of a web page semantically and HTML elements are the building blocks of HTML pages.

HTML runs natively in every web browser. When working with HTML, simple code structures (tags and attributes) are used to mark up a website page. To identify HTML documents, they are files that end with a .html or .htm extension.

HTML is not a programming language, because it doesn't have the ability to be used as functional purposes, it can only be used for structural purposes. HTML only contains a set of rules for encoding documents in a format that is both human and machine readable.

HTML is also not a sequential programming language (Sequential languages are languages that were designed for writing sequential programs), as one cannot encode logical instructions to a computer processor using HTML.

7 0

3 years ago