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
Maru [420]
3 years ago
10

How does air pressure change with altitude?

Physics
1 answer:
charle [14.2K]3 years ago
3 0
Air pressure changes with altitude because of issues related to gravity. Molecules have more weight the closer they are to the Earth and more of them move to lower elevations as a result; this causes increased pressure because there are more molecules in number and proximity. Conversely, air at higher elevations has less weight, but also forces pressure on those layers below it, resulting in the molecules closer to the Earth supporting more weight, increasing the pressure
You might be interested in
In the formula used to solve problems related to the first law of thermodynamics, what does Q represent? A.internal energy
Blizzard [7]
B, heat, is the correct answer. Heat is represented by a capital q in thermodynamic equations.
7 0
3 years ago
Read 2 more answers
How is the independent variable affected by the dependent variable
stiv31 [10]

Answer:

A dependent variable is a variable that is tested in an experiment. An independent variable is that can be modified. Depending on what you are testing, the dependent variable will change accordingly to the dependent variable.

- I'm reading this back and it doesn't make much sense, if you want me to reword this I can

5 0
2 years ago
Steam flows steadily through an adiabatic turbine. The inlet conditions of the steam are 4 MPa, 500◦C, and 80 m/s, and the exit
Cerrena [4.2K]

Answer:

a) ΔEC=-23.4kW

b)W=12106.2kW

c)A=0.01297m^2

Explanation:

A)

The kinetic energy is defined as:

\frac{m*vel^2}{2} (vel is the velocity, to differentiate with v, specific volume).

The kinetic energy change will be: Δ (\frac{mvel^2}{2})=\frac{m*vel_2^2}{2}-\frac{m*vel_1^2}{2}

Δ (\frac{mvel^2}{2})=\frac{m}{2}*(vel_2^2-vel_1^2)

Where 1 and 2 subscripts mean initial and final state respectively.

Δ(\frac{mvel^2}{2})=\frac{12\frac{kg}{s}}{2}*(50^2-80^2)\frac{m^2}{s^2}=-23400W=-23.4kW

This amount is negative because the steam is losing that energy.

B)

Consider the energy balance, with a neglective height difference: The energy that enters to the turbine (which is in the steam) is the same that goes out (which is in the steam and in the work done).

H_1+\frac{m*vel_1^2}{2}=H_2+\frac{m*vel_2^2}{2}+W\\W=m*(h_1-h_2)+\frac{m}{2} *(vel_1^2-vel_2^2)

We already know the last quantity: \frac{m}{2} *(vel_1^2-vel_2^2)=-Δ (\frac{mvel^2}{2})=23400W

For the steam enthalpies, review the steam tables (I attach the ones that I used); according to that, h_1=h(T=500C,P=4MPa)=3445.3\frac{kJ}{kg}

The exit state is a liquid-vapor mixture, so its enthalpy is:

h_2=h_f+xh_{fg}=289.23+0.92*2366.1=2483.4\frac{kJ}{kg}

Finally, the work can be obtained:

W=12\frac{kg}{s}*(3445.3-2438.4)\frac{kJ}{kg} +23.400kW)=12106.2kW

C) For the area, consider the equation of mass flow:

m=p*vel*A where p is the density, and A the area. The density is the inverse of the specific volume, so m=\frac{vel*A}{v}

The specific volume of the inlet steam can be read also from the steam tables, and its value is: 0.08643\frac{m^3}{kg}, so:

A=\frac{m*v}{vel}=\frac{12\frac{kg}{s}*0.08643\frac{m^3}{kg}}{80\frac{m}{s}}=0.01297m^2

Download pdf
7 0
3 years ago
What frequency fapproach is heard by a passenger on a train moving at a speed of 18.0 m/s relative to the ground in a direction
Sergio039 [100]

Answer:

The frequency is 302.05 Hz.

Explanation:

Given that,

Speed = 18.0 m/s

Suppose a train is traveling at 30.0 m/s relative to the ground in still air. The frequency of the note emitted by the train whistle is 262 Hz .

We need to calculate the frequency

Using formula of frequency

f'=f(\dfrac{v+v_{p}}{v-v_{s}})

Where, f = frequency

v = speed of sound

v_{p} = speed of passenger

v_{s} = speed of source

Put the value into the formula

f'=262\times(\dfrac{344+18}{344-30})

f'=302.05\ Hz

Hence, The frequency is 302.05 Hz.

7 0
3 years ago
Balanced forces acting on an object cause the object to accelerate. Please select the best answer from the choices provided T F
Pani-rosa [81]
False
Balanced forces mean that there is no net force acting on the object. therefore, the object will not accelerate.
7 0
3 years ago
Other questions:
  • When applying the process of science which of theseis tested 1.a question, 2.an observation, 3.a conclusion, 4.a prediction
    14·2 answers
  • 1.)Which is the correctly balanced equation?
    6·1 answer
  • A tow truck drags a stalled car along a road. The chain makes an angle of 30° with the road and the tension in the chain is 1400
    8·1 answer
  • The floor of a railroad flatcar is loaded with loose crates having a coefficient of static friction of 0.480 with the floor. If
    12·1 answer
  • The angle of reflection is the angle between the normal line and the___?
    13·1 answer
  • Electrical energy is used to turn the blades of a fan. The amount of energy transformed is seen here : 750 J electrical energy i
    10·1 answer
  • The term fetus completes which of the following lists to show the correct order of development?
    12·1 answer
  • Match the technology that uses radio waves to the field in which it is used.
    5·1 answer
  • The diagram shows the electric field near conducting sphere a which of the following statements is correct
    15·1 answer
  • When we say charge is conserved, we mainly mean that charge can be _________. View Available Hint(s)for Part A constant in all b
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!