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
aliina [53]
3 years ago
8

A closed, rigid tank fitted with a paddle wheel contains 2.0 kg of air, initially at 200oC, 1 bar. During an interval of 10 minu

tes, the paddle wheel transfers energy to the air at a rate of 1 kW. During this time interval, the air also receives energy by heat transfer at a rate of 0.5 kW. These are the only energy transfers. Assume the ideal gas model for the air, and no overall changes in kinetic or potential energy. Do not assume specific heats are constant. Determine the change in specific internal energy for the air, in kJ/kg, and the final temperature of the air, in oC.
Engineering
1 answer:
RUDIKE [14]3 years ago
8 0

Answer:

T=833.8 °C

Explanation:

Given that

m= 2 kg

T₁=200 °C

time ,t= 10 min = 600 s

Work input = 1 KW

Work input = 1 x 600 KJ=600 KJ

Heat input = 0.5 KW

Q= 05 x 600 = 300 KJ

Gas is ideal gas.

We know that for ideal gas internal energy change given as

ΔU= m Cv ΔT

For air Cv= 0.71 KJ/kgK

From first law of thermodynamics

Q  = ΔU +W

Heat input taken as positive and work in put taken as negative.

300 KJ = - 600 KJ + ΔU

ΔU = 900 KJ

ΔU= m Cv ΔT

900 KJ = 2 x 0.71 x (T- 200 )

T=833.8 °C

So the final temperature is T=833.8 °C

You might be interested in
A motor car shaft consists of a steel tube 30 mm internal diameter and 4 mm thick. The engine develops 10 kW at 2000 r.p.m. Find
tresset_1 [31]

The maximum shear stress in the tube when the power is transmitted through a 4: 1 gearing is 28.98 MPa.

<h3>What is power?</h3>

Power is the energy transferred per unit time.

Torque is find out by

P = 2πNT/60

10000 = 2π x 2000 x T / 60

T =47.74 N.m

The gear ratio Ne / Ns =4/1

Ns =2000/4 = 500

Ts =Ps x 60/(2π x 500)

Ts =190.96 N.m

Maximum shear stress τ = 16/π x (T / (d₀⁴ - d₁⁴))

τ max =T/J x D/2
where d₁ = 30mm = 0.03 m

           d₀ = 30 +(2x 4) = 38mm =0.038 m

Substitute the values into the equation, we get

τ max = 16 x 190.96 x 0.038 /π x (0.038⁴ - 0.03⁴)

τ max = 28.98 MPa.

Thus, the maximum shear stress in the tube is 28.98 MPa.

Learn more about power.

brainly.com/question/13385520

#SPJ1

7 0
2 years ago
A vertical pole consisting of a circular tube of outer diameter 127 mm and inner diameter 115 mm is loaded by a linearly varying
Anna [14]

Maximum shear stress in the pole is 0.

<u>Explanation:</u>

Given-

Outer diameter = 127 mm

Outer radius,r_{2} = 127/2 = 63.5 mm

Inner diameter = 115 mm

Inner radius, r_{1} = 115/2 = 57.5 mm

Force, q = 0

Maximum shear stress, τmax = ?

 τmax  = \frac{4q}{3\pi } (\frac{r2^2 + r2r1 + r1^2}{r2^4 - r1^4} )

If force, q is 0 then τmax is also equal to 0.

Therefore, maximum shear stress in the pole is 0.

3 0
3 years ago
Statement true about fats in food
Elodia [21]

Answer:

What that means please explain

7 0
3 years ago
Read 2 more answers
Kerosene flows through 3/4 standard type K drawn copper tube. The pressure drop measured at two points 50 m apart is 130 kPa. De
jok3333 [9.3K]

Answer:

Q=4.98\times 10^{-3}\ m^3/s.

Explanation:

Given that

L= 50 m

Pressure drop = 130 KPa

copper tube is 3/4 standard type K drawn tube.

From standard chart ,the dimension of 3/4 standard type K copper tube given as

Outside diameter=22.22 mm

Inside diameter=18.92 mm

Dynamic viscosity for kerosene

\mu =0.00164\ Pa.s

We know that

\Delta P=\dfrac{128\mu QL}{\pi d_i^4}

Where Q is volume flow rate

L is length of tube

d_i is inner diameter of tube

ΔP is pressure drop

μ is dynamic viscosity

Now by putting the values

\Delta P=\dfrac{128\mu QL}{\pi d_i^4}

130\times 1000=\dfrac{128\times 0.00164\times 50Q}{\pi \times 0.01892^4}

Q=4.98\times 10^{-3}\ m^3/s

So flow rate is Q=4.98\times 10^{-3}\ m^3/s.

6 0
3 years ago
Travel Time Problem: Compute the time of concentration using the Velocity, Sheet Flow Method for Non-Mountainous Orange County a
Vaselesa [24]

Answer:

Total time taken = 0.769 hour

Explanation:

using the velocity method

for sheet flow ;

Tt = \frac{0.007(nl)^{0.8} }{(Pl)^{5}s^{0.4}  }  

Tt = travel time

n = manning CaH

Pl = 25years

L = how length ( ft )

s = slope

For Location ( 1 )

s = 0.045

L = 1000 ft

n = 0.06 ( from manning's coefficient table )

Tt1 = 0.128 hour

For Location ( 2 )

s = 2.5 %

L= 750

n = 0.13

Tt2 = 0.239 hour

For Location ( 3 )

s = 1.5%

L = 500 ft

n = 0.15

Tt3 = 0.237  hour

For Location (4)

s = 0.5 %

L = 250 ft

n = 0.011

Tt4 = 0.165 hour

hence the Total time taken = Tt1 + Tt2 + Tt3 + Tt4

                                              = 0.128 + 0.239 + 0.237 + 0.165 = 0.769 hour

5 0
3 years ago
Other questions:
  • When a mesh in a circuit contains an independent or dependent current source, this leads to a special case of mesh-current analy
    14·1 answer
  • for high-volume production runs, machining parts from solid material might not be the best choice of manufacturing operations be
    12·1 answer
  • All circuits need three basic parts: an energy source, wires, and the object that is going to change the electrical energy into
    5·2 answers
  • A DC generator turns at 2000 rpm and has an output of 200 V. The armature constant is 0.5 V-min/Wb, and the field constant of th
    6·2 answers
  • A semiconductor is a solid substance that has a conductivity between that of an insulator and that of most metals. (True , False
    8·1 answer
  • A cylindrical specimen of a metal alloy 45.8 mm long and 9.72 mm in diameter is stressed in tension. A true stress of 378 MPa ca
    11·1 answer
  • Calculate pressure at the mid-plane of an annular cylinder of iron powder pressed using double-action press. The punch pressure
    12·1 answer
  • Refrigerant-134a enters an adiabatic compressor at -30oC as a saturated vapor at a rate of 0.45 m3 /min and leaves at 900 kPa an
    13·1 answer
  • What is brainstorming and why is it important to create the perfect solution to a problem? giving brainliest to the first answer
    11·1 answer
  • A batch of 1000 is split into 10 smaller batches of equal size 100. The processing time of each unit is 2
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!