In thermodynamics, a closed system is a system where ____

10 kg of R-134a fill a 1.115-m^3 rigid container at an initial temperature of -30∘C. The container is then heated until the pres

Sidana [21]

Answer : The final temperature an the initial pressure of gas is, 273.6 K and 177.6 kPa

Explanation :

First we have to calculate the initial pressure of gas.

As we know that, R-134a is 1,1,1,2-Tetrafluoroethane.

Using ideal gas equation:

$PV=nRT\\\\PV=\frac{w}{M}RT$

where,

P = pressure of gas = ?

V = volume of gas = $1.115m^3$

T = temperature of gas = $-30^oC=273+(-30)=243K$

R = gas constant = $8.314m^3Pa/mole.K$

w = mass of gas = 10 kg = 10000 g

M = molar mass of R-134a gas = 102.03 g/mole

Now put all the given values in the ideal gas equation, we get:

$P\times 1.115m^3=\frac{10000g}{102.03g/mole}\times (8.314m^3Pa/mole.K)\times (243K)$

$P=177587.9687Pa=177.6kPa$

Thus, the initial pressure of gas is, 177.6 kPa

Now we have to calculate the final temperature of gas.

Gay-Lussac's Law : It is defined as the pressure of the gas is directly proportional to the temperature of the gas at constant volume and number of moles.

$P\propto T$

or,

$\frac{P_1}{T_1}=\frac{P_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 177.6 kPa

$P_2$ = final pressure of gas = 200 kPa

$T_1$ = initial temperature of gas = $-30^oC=273+(-30)=243K$

$T_2$ = final temperature of gas = ?

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

$\frac{177.6kPa}{243K}=\frac{200kPa}{T_2}$

$T_2=273.6K$

Thus, the final temperature an the initial pressure of gas is, 273.6 K and 177.6 kPa

4 0

3 years ago

Quando e como surgiu a ginastica rítmica no mundo e no Brasil?

Otrada [13]

A ginástica rítmica no Brasil começou a ser praticada na década de 1960. Teve várias denominações, entre elas foi chamada de ginástica moderna e ginástica rítmica moderna e, sendo praticada essencialmente por mulheres, passou a ser chamada de ginástica feminina moderna. Depois, por decisão da Federação Internacional de Ginástica, passou à denominação de ginástica rítmica desportiva e, finalmente, ginástica rítmica.

6 0

3 years ago

A cube that is 20 nanometer on an edge contains 399,500 silicon atoms, and each silicon atom has 14 electrons and 14 protons. In

Sergeu [11.5K]

Answer:

Total 3 holes are available for conduction of current at 300K.

Explanation:

In order to develop a semiconductor, two type of impurities can be added as given below:

N-type Impurities: Pentavalent impurities e.g. Phosphorous, Arsenic are added to have an additional electron in the structure. Thus a pentavalent impurity creates 1 additional electron.
P-type Impurities: Trivalent impurities e.g. Boron, Aluminium are added to have a positive "hole" in the structure. Thus a trivalent impurity creates 1 hole.

Now for estimation of extra electrons in the impured structure is as

$N_{electrons-free}=n_{pentavalent \, atoms}\\N_{electrons-free}=4\\$

Now for estimation of "holes" in the impured structure is as

$N_{holes}=n_{trivalent \, atoms}\\N_{holes}=7\\$

Now when the free electrons and "holes" are available in the structure ,the "holes" will be filled by the free electrons therefore

$N_{holes-net}=N_{holes}-N_{electrons-free}\\N_{holes-net}=7-4\\N_{holes-net}=3$

So total 3 "holes" are available for conduction of current at 300K.

6 0

3 years ago

This is the phase of matter with no fixed shape or volume.

LUCKY_DIMON [66]

Answer: Gas

Explanation:

Matter exists in three different phases, they are:

- Solid

the phase of matter with fixed shape, high density and non-moving particles that are held together by strong bonds. Example of solids are stone and chalk

- Liquid

the phase of matter with loosely held particles that are held together and take up the shape of the containing vessel. Examples of liquid are water, orange juice

- Gas

This is the phase of matter with no fixed shape or volume, rather its molecules travel rapidly and randomly within the containing vessel. Examples of gases are ammonia and oxygen

Thus, the phase of matter with no fixed shape or volume is known as gas

3 0

3 years ago

WILL GIVE BRAINLY!! PLEASE HELPP

LekaFEV [45]

The purpose of the machine is to leverage its mechanical advantage such that the force it outputs to move the heavy object is greater than the force required for you to input.

But there's no such thing as a free lunch! When you apply the conservation of energy, the work the machine does on the object will always be equal to (in an ideal machine) or less than the work you input to the machine.

This means that you will apply a lesser force for a longer distance so that the machine can supply a greater force on the object to push it a smaller distance. That is the trade-off of using the machine: it enables you to use a smaller force but at the cost of having to apply that smaller force for a greater distance.

The answer is: The work input required will equal the work output.

8 0

3 years ago

In thermodynamics, a closed system is a system where _____