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
V125BC [204]
3 years ago
10

Determine the speed of sound in air at 400 K. Also determine the Mach number of an aircraft moving in the air at a velocity of 3

10 m/s.
The gas constant of air is R = 0.287 kJ/kg*K. Its specific heat ratio at room temperature is k = 1.4.
Engineering
1 answer:
Reika [66]3 years ago
7 0

Answer:

\alpha = \sqrt{1.4 *0.287 \frac{KJ}{Kg K}*\frac{1000J}{1KJ} *400 K}= 400.899 m/s

Ma= \frac{310 m/s}{400.899 m/s}= 0.773

Explanation:

For this case we have given the following data:

T= 400 K represent the temperature for the air

v = 310 m/s represent the velocity of the air

k = 1.4 represent the specific heat ratio at the room

R = 0.287 KJ/ Kg K represent the gas constant  for the air

And we want to find the velocity of the air under these conditions.

We can calculate the spped of the sound with the Newton-Laplace Equation given by this equation:

\alpha = \sqrt{\frac{K}{\rho}}=\sqrt{k RT}

Where K = is the Bulk Modulus of air, k is the adiabatic index of air= 1.4, R = the gas constant  for the air, \rho the density of the air and T the temperature in K

So on this case we can replace and we got:

\alpha = \sqrt{1.4 *0.287 \frac{KJ}{Kg K}*\frac{1000J}{1KJ} *400 K}= 400.899 m/s

The Mach number by definition is "a dimensionless quantity representing the ratio of flow velocity past a boundary to the local speed of sound" and is defined as:

Ma=\frac{v}{\alpha}

Where v is the flow velocity and \alpha the volocity of the sound in the medium and if we replace we got:

Ma= \frac{310 m/s}{400.899 m/s}= 0.773

And since the Ma<0.8 we can classify the regime as subsonic.

You might be interested in
What are supercapacitors ?
OLEGan [10]

Answer:

A supercapacitor, also called an ultracapacitor, is a high-capacity capacitor with a capacitance value much higher than other capacitors, but with lower voltage limits, that bridges the gap between electrolytic capacitors and rechargeable batteries.

Explanation:

6 0
3 years ago
Read 2 more answers
(TCO 4) A system samples a sinusoid of frequency 190 Hz at a rate of 120 Hz and writes the sampled signal to its output without
steposvetlana [31]

Answer:

The frequency that the sampling system will generate in its output is 70 Hz

Explanation:

Given;

F = 190 Hz

Fs = 120 Hz

Output Frequency = F - nFs

When n = 1

Output Frequency = 190 - 120 = 70 Hz

Therefore, if a system samples a sinusoid of frequency 190 Hz at a rate of 120 Hz and writes the sampled signal to its output without further modification, the frequency that the sampling system will generate in its output is 70 Hz

5 0
3 years ago
In the lab, a container of saturated soil had a mass of 113.27 g before it was placed in the oven and100.06 g after the soil had
kipiarov [429]

Answer:

  • Moisture/ water content w = 26%
  • Void ratio , e =  0.73

Explanation:

  • Initial mass of saturated soil w1 = mass of soil - weight of container

                                                 = 113.27 g - 49.31 g = 63.96 g

  • Final mass of soil after oven w2 = mass of soil - weight of container

                                                  = 100.06 g - 49.31 g = 50.75

Moisture /water content, w =   \frac{w1-w2}{w2} = \frac{63.96-50.75}{50.75} = 0.26 = 26%

Void ratio =  water content X specific gravity of solid

                  = 0.26 X 2.80 =0.728

5 0
3 years ago
Transcript
posledela

Answer:

O is truse is the best answer hhahahha

Explanation:

8 0
3 years ago
How do you determine when a truss will fail?<br> (Yield Stress)
Marat540 [252]

Answer:

If a truss buckles or overturns, it is usually because of the failure of an adjacent truss or its bracing. A steel truss in a fire may buckle and overturn because of expansion or weakening from the heat. Most truss failures are the result of broken connections. Photo 1 shows a set of parallel-chord wood trusses supporting a plywood floor deck.

Explanation:

7 0
2 years ago
Other questions:
  • For a p-n-p BJT with NE 7 NB 7 NC, show the dominant current components, with proper arrows, for directions in the normal active
    14·1 answer
  • Is there a way to get the answers to a NCCER book test?
    7·1 answer
  • 4. At what temperature does an engine run cleanest with least wear?
    11·1 answer
  • typedef struct bitNode { int data; struct bitNode *left; struct bstNode *right; } bstNode; int solve(bstNode* root) { if (root =
    15·1 answer
  • What is a network? I'LL MARK BRAINLEST
    12·2 answers
  • You rent an apartment that costs $1800 per month during the first year, but the rent is set to go up 11,5% per year. What would
    12·1 answer
  • Who is the strongest avenger i say hulk but who knows at this point
    7·2 answers
  • A new approval process is being adapted by Ursa Major Solar. After an opportunity has been approved, the contract is sent to the
    9·1 answer
  • Which type of artificial intelligence (ai) can repeatedly perform tasks of limited scope?
    8·1 answer
  • What is the creative process that helps you overcome writer's block called?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!