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
Andrews [41]
3 years ago
6

Air at 1.3 bar, 500 K and a velocity of 40 m/s enters a nozzle operating at steady state and expands adiabatically to the exit,

where the pressure is 0.85 bar and velocity is 250 m/s. For air modeled as an ideal gas with k = 1.4, determine for the nozzle: (a) the temperature at the exit, in K, and (b) the percent isentropic nozzle efficiency.
Physics
1 answer:
klio [65]3 years ago
3 0

Given:

Pressure, P = 1.3 bar

Temperature, T = 500 K

velocity, v = 40 m/s

Pressure, P' = 0.85 bar

velocity, v' = 250 m/s

k = 1.4

Solution:

Now, we know that:

specific heat at constant pressure, C_{p} = 1.005 KJ/kgK

specific heat at constant volume, C_{p} = 1.005 KJ/kgK

k = \frac{C_{p}}{C_{V}}

(a) To calculate temperature at exit, T'

Using steady flow Eqn:

h + \frac{v^{2}}{2} = h' + \frac{v'^{2}}{2}                  (1)

where

h = enthalpy = C_{p}T

h'= C_{p}T'

Now, from eqn (1)-

h + \frac{v^{2}}{2} = h' + \frac{v'^{2}}{2}

C_{p}T + \frac{v^{2}}{2} = C_{p}T' + \frac{v'^{2}}{2}

1005\times 500 + \frac{40^{2}}{2} = 1005\times T' + \frac{v'^{2}}{2}

             

T' = 469.70 K

(b) To calculate % isentropic nozzle efficiency:

Using the relation:

\frac{T_{2s}}{T} = (\frac{P'}{P})^\frac{k - 1}{k}

⇒ \frac{T_{2s}}{500} = (\frac{0.85}{1.3})^\frac{1.4 - 1}{1.4}

{T_{2s} = 0.88 \times 500 = 442.84 K

Now,

% isentropic nozzle efficiency, \eta =\frac{T - T' }{T - T_{2s}}\times 100

%  \eta =\frac{500 - 469.70 }{500 - 442.84}\times100 = 53.00 %

\eta = 53.00 %

You might be interested in
A spherical shell contains three charged objects. The first and second objects have a charge of − 14.0 nC and 33.0 nC , respecti
matrenka [14]

Explanation:

Formula depicting relation between total flux and total charge Q is as follows.

              \phi  = \frac{Q}{\epsilon_{o}}    (Gauss's Law)

Putting the given values into the above formula as follows.

            Q = \phi \times \epsilon_{o}

                = -953 Nm^{2}/C \times 8.854 \times 10^{-12}

                = -8.4 \times 10^{-9} C

                = -8.4 nC

Therefore, when the unknown charge is q  then,

         -14.0 nC + 33.0 nC + q = -8.4 nC

               q = -27.4 nC

Thus, we can conclude that charge on the third object is -27.4 nC.

7 0
3 years ago
A balloon filled with helium gas at 1.00 atm occupies 15.6 L. Will the volume of the balloon increase or decrease in the upper a
Mariana [72]

Answer:

The volume of the balloon increases in the upper atmosphere.

Explanation:

p1= 1 atm

p2= 0.15 atm

V1= 15.6 L

V2= ?

p1*V1= p2 * V2

V2= (p1/p2)*V1

V2= 104 L

6 0
3 years ago
do constructive inference occur when the compression of one wave meets up with the compression of a second wave
Ugo [173]

Answer:

Yes

Explanation:

There are two types of interference possible when two waves meet at the same point:

- Constructive interference: this occurs when the two waves meet in phase, i.e. the crest (or the compression, in case of a longitudinale wave) meets with the crest (compression) of the other wave. In such a case, the amplitude of the resultant wave is twice that of the original wave.

- Destructive interferece: this occurs when the two waves meet in anti-phase, i.e. the crest (or the compression, in case of a longitudinal wave) meets with the trough (rarefaction) of the other wave. In this case, the amplitude of the resultant wave is zero, since the amplitudes of the two waves cancel out.

In this problem, we have a situation where the compression of one wave meets with the compression of the second wave, so we have constructive interference.

6 0
3 years ago
A man attaches a divider to an outdoor faucet so that water flows through a single pipe of radius 9.25 mm into four pipes, each
irinina [24]

Answer:

1.24 m/s

Explanation:

Metric unit conversion:

9.25 mm = 0.00925 m

5 mm = 0.005 m

The volume rate that flow through the single pipe is

\dot{V} = vA = 1.45 * \pi * 0.00925^2 = 0.00039 m^3/s

This volume rate should be constant and divided into the 4 narrower pipes, each of them would have a volume rate of

\dot{V_n} = \dot{V} / 4 = 0.00039 / 4 = 9.74\times10^{-5} m^3/s

So the flow speed of each of the narrower pipe is:

v_n = \frac{\dot{V_n}}{A_n} = \frac{\dot{V_n}}{\pi r_n^2}

v_n = \frac{9.74\times10^{-5}}{\pi 0.005^2} = 1.24 m/s

8 0
3 years ago
A student who weighs 750 newton’s runs up the steps (which have a height of 8 meters) in 13.5 seconds. How much work did the stu
nikklg [1K]

Answer:

B

Explanation:

6 0
2 years ago
Other questions:
  • 2 toy cars move horizontally toward each other. When they are 40m apart one has an initial velocity of 6m/s and acceleration of
    9·1 answer
  • A rocket, weighing 4.36 x 10^4 N, has an engine that provides an upward force of 8.90 x 10^5 N. It reaches a maximum speed of 86
    6·1 answer
  • Elias stretches a rubber band and let's it go. The rubber band flies across the room. Elias says this demonstrates the transform
    11·1 answer
  • A certain spring exerts a nonlinear force given by F(x) = −60x − 18x2 , where x is in meters and F is in newtons. A 0.90-kg bloc
    10·1 answer
  • The potential difference between two parallel plates is 227 V. If the plates are 6.8 mm apart, what is the electric field betwee
    9·1 answer
  • A 5.8 kg bowling ball is rolling down the lane with a velocity of 8.1 m/s . Calculate the momentum of the bowling ball. Provide
    11·1 answer
  • What percentage of the acceleration at Earth's surface is the acceleration due to gravity at the position of a satellite located
    8·1 answer
  • A uniform rod is hung at one end and is partially submerged in water. If the density of the rod is 5/9 that of water, find the f
    14·1 answer
  • Imagine that you are sitting on a couch watching TV and that you will continue sitting on the couch watching TV until someone ch
    8·1 answer
  • What is the correct answer?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!