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
Inessa05 [86]
3 years ago
7

A mass of 1.9 kg of air at 120 kPa and 24°C is contained in a gas-tight, frictionless piston–cylinder device. The air is now com

pressed to a final pressure of 600 kPa. During the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. Calculate the work input during this process. Take the gas constant of air as R = 0.287 kJ/kg·K.
Engineering
1 answer:
emmainna [20.7K]3 years ago
6 0

Answer:

W=-260.66 kJ (negative answer means, that the work was done on the gas)

Explanation:

1) Convert temperature from C to K- T=24+273=297K- all temperature in the gas problems should be used in Kelvins;

2) We need to analyse type of the process- it is given, that the temperature is constant, so it is an Isothermal process, which means, that the equation of the process is: pV=const (constant);

3) Work, done on the system, should be calculated using the following equation: W=\int\limits^{Vb}_{Va} {p} \, dV

4) To calculate initical and final volumes (Va and Vb), we can use the following equation: pV=mRT, so V=mRT/p. Note, that the pressure is changing, thus we can calculate volumes for the both cases- initial and final, using initial (120kPa) and final (600kPa) pressures, in addition, we can find equation for the pressure, as function of the volume, which we need to use for the integration in step 3: p=mRT/V;

5) Now we can calculate the integral, given in the step 3: W=mRT ln(\frac{Vb}{Va}). As we have pressure as a known values, we can re-write the equation, using pressures: W=mRT ln(\frac{pa}{pb})=1.9*0.287*279*ln(\frac{120}{160})=-260.66 kJ

Note, that natural logarithm (ln) yields negative answer, which supports the question, that the work was done on the gas, not by the gas.

You might be interested in
Write a Python program that does the following. Create a string that is a long series of words separated by spaces. The string i
dybincka [34]

Answer:

The code is attached.

Explanation:

I created a string s including 6 colors with spaces in between. Then I converted the string into a list x by using split() method. I used three different methods for removing elements from the list. These methods are remove(), pop() and del.

\\ Then I used methods append(), insert() and extend() for adding elements to the list.

\\ Finally I converted list into a string using join() and adding space in between the elements of the list.

4 0
4 years ago
3. Which of the following is an example of qualitative data?
ad-work [718]

Answer:

Number of Items

5 0
3 years ago
Engineers are designing a cylindrical air tank and are trying to determine the dimensions of the tank. The proposed material for
lana66690 [7]

Answer:

The length of tank is found to be 0.6 m or 600 mm

Explanation:

In order to determine the length, we need to find a volume for the tank.

For this purpose, we use ideal gas equation:

PV  = nRT

n = no. of moles = m/M

Therefore,

PV = (m/M)(RT)

V = (mRT)/(MP)

where,

V = volume of air = volume of container

m = mass of air = 4.64 kg

R = General Gas Constant = 8.314 J/mol.k

T = temperature of air = 10°C + 273 = 283 K

M = molecular mass of air = 0.02897 kg/mol

P = Pressure of Air = 20 MPa = 20 x 10^6 N/m²

V = (4.64 kg)(8.314 J/mol.k)(283 k)/(0.02897 kg/mol)(20 x 10^6 N/m²)

V = 0.01884 m³

Now, the volume of cylindrical tank is given as:

V = 0.01884 m³ = π(Diameter/2)²(Length)

Length = (0.01884 m³)(4)/π(0.2 m)²

<u>Length = 0.6 m = 600 mm</u>

4 0
3 years ago
Who here is a genius?
Pachacha [2.7K]

Answer:

im kinda smart  whyy?

Explanation:

3 0
3 years ago
Read 2 more answers
Harmonic excitation of motion is represent as
Gennadij [26K]

Harmonic excitation refers to a sinusoidal external force of a certain frequency applied to a system. ... Resonance occurs when the external excitation has the same frequency as the natural frequency of the system. It leads to large displacements and can cause a system to exceed its elastic range and fail structurally.

6 0
3 years ago
Other questions:
  • . Carly's Catering provides meals for parties and special events. In Chapter 2, you wrote an application that prompts the user f
    10·1 answer
  • You are considering purchasing a compact washing machine, and you have the following information: The Energy Guide claims an est
    8·1 answer
  • In the given circuit, V(t)=12cos(2000t+45)V, R1=R2=2Ω, L1=L2=L3=3mH and C1=250μF. You are required to find the Thevenin equivale
    7·1 answer
  • Steam enters an adiabatic condenser (heat exchanger) at a mass flow rate of 5.55 kg/s where it condensed to saturated liquid wat
    11·1 answer
  • True or false the camshaft is always located in the engine block
    10·1 answer
  • Which is a better hydraulic cross section for an open channel: one with a small or a large hydraulic radius?
    13·1 answer
  • What is the purpose of the graphic language?
    15·1 answer
  • A continuously variable transmission:
    13·1 answer
  • A(n) _____________ is used commonly in open split-phase motors to disconnect the start winding from the electrical circuit when
    5·1 answer
  • Whose responsibility is it to provide direction on correct ladder usage?<br> select the best option.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!