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
Vilka [71]
3 years ago
11

Derivation 1.2 showed how to calculate the work of reversible, isothermal expansion of a perfect gas. Suppose that the expansion

is reversible but not isothermal and that the temperature decreases as the expansion proceeds. (a) Find an expression
Physics
1 answer:
stellarik [79]3 years ago
6 0

Answer:

(a) The work done by the gas on the surroundings is, 17537.016 J

(b) The entropy change of the gas is, 73.0709 J/K

(c) The entropy change of the gas is equal to zero.

Explanation:

(a) The expression used for work done in reversible isothermal expansion will be,

where,

w = work done = ?

n = number of moles of gas  = 4 mole

R = gas constant = 8.314 J/mole K

T = temperature of gas  = 240 K

= initial volume of gas  =  

= final volume of gas  =  

Now put all the given values in the above formula, we get:

The work done by the gas on the surroundings is, 17537.016 J

(b) Now we have to calculate the entropy change of the gas.

As per first law of thermodynamic,

where,

= internal energy

q = heat

w = work done

As we know that, the term internal energy is the depend on the temperature and the process is isothermal that means at constant temperature.

So, at constant temperature the internal energy is equal to zero.

Thus, w = q = 17537.016 J

Formula used for entropy change:

The entropy change of the gas is, 73.0709 J/K

(c) Now we have to calculate the entropy change of the gas when the expansion is reversible and adiabatic instead of isothermal.

As we know that, in adiabatic process there is no heat exchange between the system and surroundings. That means, q = constant = 0

So, from this we conclude that the entropy change of the gas must also be equal to zero.

Explanation:

You might be interested in
Find the equivalent resistance of this parallel circuit with two strands.
svlad2 [7]
In a parallel circuit, the total resistance calculated from the individual resistances is computed from the formula: 1/Rt = 1/R1 + 1/R2. substituting R1 and R2, then 
1/Rt = 1/7 + 1/49 
1/Rt = 1/6.125 = 1/ 49/8
Rt = 49/8 <span>Ω

The total resistance hence is </span>49/8 Ω
6 0
3 years ago
Look at the Sankey diagram for a filament light bulb below. If the bulb is used in a desk lamp, what is the efficiency of the bu
guapka [62]

Answer:

The question does not state how the answer is to be entered. I would use 10% because that is most common.

Explanation:

You are using 300 J of energy to get 30 J of light energy. The fact that you can account for the left over energy is not relevant.

Efficiency = Work Out / Work In

Efficiency = 30 J / 300 J  = 0.1

If you need this as a %, you can multiply by 100

Efficiency = 0.1 * 100 = 10%

6 0
2 years ago
Calculate the ratio of the drag force on a jet flying at 950 km/h at an altitude of 10 km to the drag force on a prop-driven tra
Black_prince [1.1K]

Answer:

\frac{F_1}{F_2}=3.55

Explanation:

F = Force

C = Drag coefficient equal for both aircrafts

ρ = Density of air

A = Surface area equal for both aircrafts

v = Velocity

v_2=\frac{2}{5}v_1

F_1=\frac{1}{2}\rho_1 CAv_1^2

F_2=\frac{1}{2}\rho_2 CAv_2^2\\\Rightarrow F_2=\frac{1}{2}\rho_2 CA\left(\frac{2}{5}v_1\right)^2

Dividing the above two equations we get

\frac{F_1}{F_2}=\frac{\frac{1}{2}\rho_1 CAv_1^2}{\frac{1}{2}\rho_2 CA\left(\frac{2}{5}v_1\right)^2}\\\Rightarrow \frac{F_1}{F_2}=\frac{\rho_1}{\rho_2\frac{4}{25}}\\\Rightarrow \frac{F_1}{F_2}=\frac{0.38}{0.67\frac{4}{25}}\\\Rightarrow \frac{F_1}{F_2}=3.55

The ratio of the drag forces is \mathbf{\frac{F_1}{F_2}}=\mathbf{3.55}

5 0
3 years ago
The orbital period of a satellite is 2 × 106 s and its total radius is 2.5 × 1012 m. The tangential speed of the satellite, writ
LenaWriter [7]

The orbital period of the satellite[T] is given as 2*10^{6} S.

The radius of the satellite is given [R] 2.5*10^{12} m.

we are asked here to calculate the tangential speed of the satellite.

Before going to get the solution first we have understand the tangential speed.

The tangential speed of a satellite is given as the speed required to keep the satellite along the orbit. If satellite speed is less than tangential speed,there is the chance of it falling down towards earth. If it is more,then it will deviate from it orbit and can't stick to the orbit further.In a simple way  the tangential speed is the linear speed of an object in a circular path.

Now we have to calculate the tangential speed [V].

Mathematically the tangential speed [V]   written as -

                                V=\frac{2\pi R}{T}

where T is the time period of the satellite and R is the radius of the satellite.

                        V=\frac{2*3.14*10^{12} }{2*10^{6} }

                               = 7.85*10^{6} m/s

There is also another way through which we can get  the solution as explained below-

We know that the tangential speed of a satellite V=\sqrt{\frac{GM}{R^{2} } }

where G is the gravitational constant and M is the mas of central object.

But we know that g=\frac{GM}{R^{2} }

                               ⇒GM=gR^{2}  where g is the acceleration due to gravity of that central object.


Hence    V=\sqrt{\frac{gR^{2} }{R} }

               ⇒   V=\sqrt{gR}

By knowing the value of g due to that central object we can also calculate its tangential speed.

                           

 




7 0
3 years ago
Read 2 more answers
Bird bones have air pockets in them to reduce their weight–this also gives them an average density significantly less than that
lakkis [162]

Answer:

a)39ml

b)39g

c)1.1g/ml

Explanation:

Hello!

To solve this exercise use the following steps

1. When Archimedes discovered how to determine the irregular volume of an object by weighing it in the air and in an algua, he found that its volume is equal to the ratio between the differences of the masses (heavy in the air and in the water) and the density of the water (= 1g / ml)

V=\frac{43g-3.6g}{1g/ml} =39.4ml

2.as the principle of archimedes says, the displaced volume of water is equal to the volume of the bone which means that 39.4ml of water was displaced, taking into account that the density of water is the ratio between mass and volume we can determine the displaced body of water

density=\frac{m}{V} \\m=V(density)\\m=(39ml)(1g/ml)=39g

3. we use the density equation to find the bone density

density=\frac{43g}{39ml} =1.1g/ml

8 0
3 years ago
Other questions:
  • A circuit contains a 1.5v battery and a bulb with a 3 ohms resistance, calculate the current of the circuit
    14·1 answer
  • Before leaving an incident assignment, you should do all of the following EXCEPT FOR:
    9·1 answer
  • Why do we warm up when we wear warm clothes? Explain the hiccup from the point of view of physics.
    5·1 answer
  • The net electric charge of an amber rod which has been rubbed with fur is called negative Group of answer choices because amber
    6·1 answer
  • Pin p is constrained to move along the curve defined by the lemniscate r=(4sin2θ)ft.if the slotted arm oa rotates counterclockwi
    7·1 answer
  • Why are Carbon-14 and carbon-12 considered to be isotopes?
    10·1 answer
  • What is the difference between a contact force and a non-contact force?
    8·1 answer
  • Please help meee!!!!!
    8·2 answers
  • A toy car rolls at a constant speed down a straight
    15·2 answers
  • What is the current in a circuit if the charge passing each point is 10current <br>in 2s​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!