F338-Hukum 2 termodinamika ,perumusan Kelvin-Planck ,Clausius dan entropi

Hello hello

fans and physics lovers

this time I will explain about the

2nd law of thermodynamics

The first 2nd law of thermodynamics formulated by

Kelvin-Planck is about combustion engines it is

impossible to make an engine that draws

heat from high tendons and converts it

all into mechanical work So

if for example Here you have a

hot reservoir for example for a gasoline engine when it is

burned it will produce heat right Well

if this is all converted

into mechanical work it is impossible that

if it is possible like this wow this

can be perfectly economical Your engine so buy

1 liter of gasoline it is all burned into heat

all into mechanical work Well that is

very impossible yes Hi well

this is what is meant by

the laws of the thermometer the Kelvin-Planck formula

well what happens in nature is like

this a real engine is like this it

burns gasoline usually a combustion engine

here burns gasoline the calories that appear are

not all converted into

mechanical work some are also thrown out through the

exhaust

Is there a motorbike car that does not

have an exhaust it must have an exhaust

because the heat that is taken the heat that is

taken is not all Duba becomes

mechanical work but some are thrown out

through the exhaust that is the clear engine in

this world like this Well the second one is

Clausius's formula so the

thermohygrometer laws by Clausius are

about the cooling machine, it is impossible to

flow heat from low temperature to

high temperature without external effort

Hi so for example here there is a responsibility to

shoot this year this low element has a

high temperature which contains low calories

it must flow from high temperature to

lower temperature It cannot be

reversed from low to high

for example the temperature in your room is

successful Brazzers then the door is opened

it must be

hot air flowing from

your environment to the room and it cannot be reversed

like that so the heat flow is

naturally spontaneous from high temperature to

lower temperature for sure

hi why what if we for example

want to flow heat from low temperature

to high temperature it is possible but it must be

with external effort well this is what

was said earlier yes it is impossible to

flow heat from low temperature to

high temperature without me realizing outside Well

if there is external effort you can

flow heat from the lowest reservoir

to Syria higher for example this

is how a real cooling machine works

so a cooling machine for example AC

draws heat from inside the

cooled room to its environment which has a

higher temperature but that is with

electrical effort yes So if you have an

AC that is not plugged in,

you will not turn on the

electricity, it

will not cool your room, there is no heat

drained, the family temperature is

higher like that

Hi Well now 02.00 thermodynamics the

third formulation is about entropy

Nahin trophy the universe always increases

in an irreversible process and

there is always a Princess Belle process

Hi Well later I will explain what the

irreversible and reversible processes

Nahin trophy that I explained first what

is the intro Pi entropy is a measure of the

amount of heat energy that cannot be

converted into work for example in a

piston engine it will rub against

the cylinder Well if it rubs it

produces heat how much of the necklace

can be converted into work, it cannot,

instead the heat that appears is detrimental to the

work so the engine's work will be

reduced like that Because there is something that

turns into heat like that

Hi well then secondly there are

also those who define intropia

as the level of the system's energy state

the more energy it has, the

greater the entropy for example you

imagine there is a metal the

left end is very hot the right end is

very cold if the left end is very

hot while the right end is

very cold Well that means the energy is

localized like that from the heat

on the left The cold on the right Well that is

said to be not random energy but

over time it flows to Hi Sis Nur

flowing from the hot end to the

cold end finally the heat is evenly distributed if

the heat is evenly distributed it is said to be

random energy meaning the instructions are increasing like that

Well entropy can also be said

to be the level of disorder of the system

for example imagine there is a room filled with

30 students, the

students are studying comfortably,

suddenly the room is burned, what

happens then all the students will definitely run

helter-skelter the system is in a

more chaotic state like that

Sis maybe it is getting calmer when there is a

fire Wow never mind, yes, death is made by

that experience is impossible,

the students will definitely all spray out Well

that means the system is said to be

disordered and assume the students were

gas particles, yes, of course the refrigerator if

heated is also like that more

Wrong Behavior the system is said to be

increasingly disordered if it is increasingly

disordered then it is said that the entropy

increases like that Well if at a constant temperature the

entropy change that occurs

is delta Cipete how is Delta the

heat change that occurs while

teto is the temperature

well Delta es the entropy change is

always 0ad meaning

entropy The universe is always right

on the reversible process,

the reversible process is a process that can Bale

means the process can be returned

so that the

thermodynamic components

related to pressure, volume, temperature

can really be returned

to their original state

Hi, the reversible process is usually a

very slow process or a

quasistatic process,

so the quasistatic process means

the process that takes place at

any time can be said between the system

and its environment is in a state of

equilibrium.

This means that for example the temperature of the system

with distilled water is

very small, approaching North, as well as

the volume, pressure, and

so on, so the thermodynamic components

between the system and the environment are

the difference approaching Noor

Hi, the reversible process, for example,

is the Karno cycle process. Well, later

I will give an example of it, the process

in nature is of course naturally an

irreversible process, an irreversible process

is a process that cannot be returned

to its original state, cannot be reversed, well,

this will definitely cause an increase in

the entropy of the universe So the Delta es

will be greater than zero,

for example, you know, heat and heat is

always from what, from a high temperature to a

low temperature So if for example

you open the door of your room air-conditioned,

the heat must flow from

your environment to your room, right?

Hi Well, that's an irfal process, annoying

Hi and it can't be used, bro, it

can't be reversed, so for example, 6 back

from the heat flowing from your room

naturally out, that's impossible,

so in an irreversible process, the

entropy always increases, like only the

times, it also continues to increase, right, it ca

n't be reduced, for example, your age

continues to increase. It can decrease,

but I, so your age always increases, the

years always increase, finished in 2002,

2001, 2002, and the fun part is like that, right? Well,

like your age can divide 1920 and

so on, right? So, because

in an irreversible process, the instruction

always increases, the intropia of the universe

always increases, so it's said that

entropy is an arrow of time or

time error

Hi Well, I've explained this, right? The

Delta of the istir won't change.

Another tropical one is joule per Kelvin

and again, the change in heat in the

gas system, the unit is Jul, the change

is Suga, the unit is Kelvin

Hi Well, introverted with sub rubah, it

can also happen, so the Delta of the istir is the

change The entropy can be formulated as MJ

lonte2 one box or you can use the

molar heat capacity of the gas, namely Delta

snc lonte2 or this one I have already

explained Delta es still states

the change in entropy m is the mass Unit

kg is the specific heat of the gas Jere he is large

molar heat capacity of the gas daily one

only has mall T1 swagga while T2

is a gas end

Hi watch more clearly I will

give examples of questions example questions one by one

how much is the change in entropy of the gas system

in one cycle In the Kaho cycle, so it

becomes like this, it means

my intention is to have a PV diagram of the Karno cycle, it

is a cycle that is limited by two

isothermal processes and 2 adiabatic processes

or b is an isothermal expansion process,

heat enters the system,

for example Q1, well this is a

real shooting from a to b so later T1 is

greater than T2, you

can imagine At that time the temperature in the

engine is right, burn gasoline in the engine,

for example T2 is the temperature around the

exhaust Well if it works, it is a

shallow adiabatic expansion process, the jacket

is an isothermal compression process,

compression because it occurs volume decrease

yes if expansion occurs

volume increase well T2 is the low temperature

here in the impression process technical issue

heat will be removed from the gas system if

D in that direction is the compression process there is a

babis in the adiabatic process there is no

heat exchanged between the system

and the environment so Delta giginya is zero

here also Delta kynya is zero okay well in the

Karno cycle process it applies that the story of the

one box is equal to q22 If

you don't understand why this happens

Look at my previous video which

discusses the derivation of this formula

Well if we calculate how much

entropy change occurs in the

isothermal expansion process from a to b it

is the story to party one how much heat

is entered divided by shooting that is

this isothermal expansion process Well if in

this isothermal compression process If it is removed then

Delta scdd is Minaj 22 Why

minus because this heat is removed from the

gas system Well if the total entropy change

means Delta ESAB plus

scd data Delta sapi There is another

one party one Delta sdd is

wingki2 pete2 but the carnot cycle earlier

is ideal class yes it is reversible

Well so if infosebel Q1 box 1 =

qidu or two then I can replace this

yes Q2 pete 2 becomes q1pp one well

if I add the result is

zero because Delta es now means In

this Karno cycle there is a process that

Revo sebel the process can be reversed

hi okay example of the second question Ghazali

has a molar heat capacity of 12.5

joules per mole per Kelvin in a

constant volume process If

two moles of helium gas are heated without you buffer

realizing su-300 Kelvin becomes 500 Kelvin

calculate the change in entropy Well we

Answer yes Well the change in entropy

is ncv lonte2 per

t1n that is Mal from the suit yes this

occurs at constant volume so this

is the molar heat capacity of gas at

constant volume well

then we just enter the number the

moral is two cv 12.5 t2t one

I enter jebret the result is

12.7 7 juplret Kelvin this is the change in

entropy that occurs