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
Alex Ar [27]
3 years ago
14

A piston-cylinder device contains Helium gas initially at 150 kPa, 20 o C, and 0.5m 3 . The helium is now compressed in a polytr

opic process () to 400 kPa and 140 o C. Determine the work and heat transfer done during this process.
Physics
1 answer:
Molodets [167]3 years ago
3 0

Answer:

Explanation:

Given

P_1=150 kPa

T_1=20^{\circ}C

V_1=0.5 m^3

T_2=140^{\circ}C

P_2=400 kPa

R for Helium R=2.076

c_v=3.115 kJ/kg-K

mass of gas m=\frac{P_1V_1}{RT_1}

m=\frac{150\times 0.5}{2.076\times 293}

m=0.123 kg

Similarly V_2 can be found

\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}

V_2=0.264 m^3

Work done W=\int_{V_1}^{V_2}PdV

W=\frac{P_2V_2-P_1V_1}{n-1}

W=\frac{mR(T_2_T_1)}{n-1}

Since it is a polytropic Process

therefore PV^n=c

P_1V_1^n=P_2V_2^n

(\frac{V_1}{V_2})^n=\frac{P_2}{P_1}

(\frac{0.5}{0.264})^n=\frac{400}{150}

n=\frac{\ln 2.66}{\ln 1.893}

n=1.533

W=\frac{0.123\times 2.076(140-20)}{1.533-1}

W=57.48 kJ    

From Energy balance

E_{in}-E_{out}=\Delta E_{system}

Neglecting kinetic and Potential Energy change

Q_{in}+W_{in}=change\ in\ Internal\ Energy

Change in Internal Energy \Delta U=u_2-u_1

\Delta U=mc_v(T_2-T_1)

\Delta U=0.123\times 3.115(140-20)

\Delta U=45.977 kJ

Q_{in}+57.48=45.977

Q_{in}=-11.50 kJ  

i.e. Heat is being removed

You might be interested in
Earthquake damage causes two rabbits to be separated from the rest of the rabbits in their large habitat. They have no way to ge
Sedbober [7]

Answer:

<em>A.The rabbits in the new habitat will have lower genetic variation than the rabbits in the original habitat. </em>

<em></em>

Explanation:

If two animals of opposite sex are isolated from a larger group of animal, and made to reproduce. They will produce offspring with similar genetic makeup. If this offspring still remain isolated, and continue to interbreed within themselves for a number of consecutive generations, their offspring will all be very closely related genetically. Situations like this just as with the two rabbits in the question leads to a lower genetic variation within the offspring of the two animals.

Animals need to reproduce within a larger group in order to increase genetic variation. Increasing genetic variation reduces the risk of been sucked into a gene pool. A lower genetic variation reduces the fitness of the animals involved. It is only an advantage in cases in which the the original pair are resistant to a deadly disease. In this case all the offspring also develop this immunity. Mostly the effects of a lower genetic variation leaves negative impacts, and animals try to avoid this by preferring to interbreed with unrelated partner

3 0
3 years ago
Read 2 more answers
Plzzzzzz help :(((((((((((
OlgaM077 [116]

Answer:

4. a) F

b) E

c) B

d) D

Hope it helps

7 0
3 years ago
Read 2 more answers
A person walks 2 miles every day to work, leaving her front porch at 7:00 A.M. and arriving at work at 7:30 A.M. ON the way home
Nataly [62]

Answer:

The displacement is zero miles

Explanation:

The displacement of an object that moves from point A to point B is defined as

d =B-A

Where d is the displacement of the object. The displacement does not depend on the trajectory of the object. It only depends on the linear distance between the end point and the starting point.

In this case we know that the person walks from home to work and then walks from work to home. Therefore, the total displacement is the linear distance between the point where its journey begins and the point where the route ends.

The tour begins on the front porch of your house and ends on the front porch of your house (when you return from work). If we call A to the front porch of the house then the displacement is:

d = A-A = 0

The displacement is zero miles, since the person finishes the journey just where it started (front porch)

7 0
3 years ago
Electrons can move between substances ſchree ways. Which of the following can be
Lady bird [3.3K]

Answer:

B.) “Shininess” should be explained as “Light bounces off the moving electrons.”

Explanation:

6 0
3 years ago
Matthew throws a ball straight up into the air. It rises for a period of time and then begins to drop. At which points in the ba
PolarNik [594]

Answer:

If air resistance is taken as negligible, then the ball is in freefall the moment it is thrown so gravity is the only force acting on the object. If air resistance is not negligible then gravity will be the greatest force acting on the ball while it is going up and coming down, because Fair has to be less than gravity at all times otherwise the atmosphere would wither away.

3 0
3 years ago
Other questions:
  • An iron ball and an aluminum ball of mass 100 g each are heated to the same temperature and then cooled to a temperature of 20°C
    8·1 answer
  • The peak intensity of radiation from Star Beta is 350 nm. In what spectral band is this? UV, radio waves, visible light, or infa
    10·2 answers
  • Why is hydrogen placed on the left side of the periodic table even though it is a gas
    5·2 answers
  • A 60-kg rollerblader rolls 10 m down a 30? incline. When she reaches the level floor at the bottom, she applies the brakes. The
    7·1 answer
  • An inclined plane of length 12m is used to pull a load of 3000N to height of 3m by applying an effort of 1000N. Calculate its MA
    14·1 answer
  • Generalized global air circulation and precipitation patterns are caused by
    13·2 answers
  • If you were on a ship at sea, and a tsunami passed under your ship, what would probably be your reaction? explain.
    15·1 answer
  • What is involved in a career exploration
    15·2 answers
  • I need an answer ASAP .....
    14·2 answers
  • If a melon has a a mass of 1 kg, how much does the melon weigh?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!