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
A vector has an x component of 25.0 units and a y
sammy [17]
Here is the answer to your question

8 0
3 years ago
The linear momentum of a truck of mass 5000 kg that is moving at a velocity of +30 m/a is ___ kg m/s
miv72 [106K]

Linear momentum of a truck is 1,50,000 kg.m/s

Explanation:

Linear momentum is the product of the mass and velocity of an object. It is a vector quantity, which have a magnitude and a direction.

Linear momentum is a property of an object which is in motion with respect to a reference point (i.e. any object changing its position with respect to the reference point).

It's SI units are kg.m/s

Linear momentum is a vector quantity.

Linear momentum formula (p) = mass × velocity

Given data mass = 5000 kg ; velocity = 30 m/s

P = 5000 × 30

Linear momentum p= 1,50,000 kg.m/s

7 0
3 years ago
(b) A car of mass 3000 kg travels at a constant velocity of 5.0 m/s.
Tamiku [17]

Answer:

16.7 s

Explanation:

T= <u>Vf - Vo</u>          a= <u>F</u>

         a                    m

4,500 / 3000 = 1.5 (a)

30 - 5 / 1.5(a) = 16.7 s      

4 0
3 years ago
What does vf stand for<br> a.fringe velocity<br> b.first velocity<br> c.final velocity
Elza [17]
The correct answer is C. Final Velocity

Hope this helped!
5 0
2 years ago
Two cannonballs are dropped from a second-floor physics lab at height h above the ground. Ball B has four times the mass of ball
denpristay [2]

Answer:

1:4

Explanation:

The formula for calculating kinetic energy is:

KE=\dfrac{1}{2}mv^2

If the mass is multiplied by 4, then, the kinetic energy must be increased by 4 as well. Since they will be travelling at the same speed when they are at the same point, the relation between KA and KB must be 1:4 or 1/4. Hope this helps!

3 0
3 years ago
Other questions:
  • If the resistance doubles while the voltage stays the same, what effect will that have on the power?
    12·1 answer
  • A dwarf planet discovered out beyond the orbit of Pluto is known to have an orbital period of 619.36 years. What is its average
    13·1 answer
  • Which is correct about an ammeter?
    8·1 answer
  • When energy is produced in a reaction it
    15·1 answer
  • If the pitch of the note becomes higher
    7·1 answer
  • A person standing on the edge of a high cliff throws a rock straight up with an initial velocity, v0v0, of 13.0m/s13.0m/s. on th
    11·1 answer
  • Scientists classify rocks by
    7·1 answer
  • What process occurs when all of the energy from light waves is transferred to a medium?
    10·2 answers
  • If you are sitting on a school bus, is the driver in motion (according to your
    14·1 answer
  • A boat is stationary at 12 meters away from a dock. The boat then begins to move toward the dock with
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!