Why is wave a hyperbolic and heat parabolic?

what do you mean? why is the wave equation hyperbolic and the heat equation parabolic?

it's just a matter of definition

it's like asking why is $ax^2 + bx + c = 0$ quadratic

@JohnRennie Please respond to this

@user586228 hi :-)

Yup

Respond to what? Why a wave is hyperbolic?

No why is wave equation called so

And heat equation called so

Secondly,

In my textbook it is written that the activity of the solute follows Henry's law which is stated as follows:ai= γ i ° Xi .I see this to be no different from the way Raoult's law was defined apparently.Except for the specific symbol of gamma nought.What exactly is gamma nought?Please tell me how Raoult's law and Henry's law are different from each other in the context.An in depth answer will be highly appreciated.

@user586228 that's terminology used in engineering, and I don't know the answer.

i believe those are discussed more under Chem than Phy?

yeah

@user586228 the two are closely related

@RishiNandhaVanchi Which two?

they gave me a proof of Raoults from Henry so yeah

Raoults and Henry Laws

Please help me with this @RishiNandhaVanchi

ok

then..

Henry is looking at it from a Gas dissolved in liquid perspective, Rauolts is looking at it from a Liquid vaporized to give Gaseous Pressure perspective

ok

How are they equivalent

I uh dont get what you're asking tbh

you can show Raoults with Henry so you can call them equivalent right?

What is Henrian coefficient.

Kh i believe

Henry Law constant

ohh okk....

as what we call it

Thanks for hep

np

:)

Btw do you go to any IITJEE coaching centre?

What is it?

Yeah

fiitjee

Ohh thats great..How was ur FTRE?

i didnt write this year lol

just a moment I was going to ask sir something

How much scholarship r u getting

Ok

@JohnRennie are you free sir?

@RishiNandhaVanchi hi :-)

hi sir :->

the solution given looks like a fake solve, im not really sure what to do. I marked A

The blast wave will move at the speed of sound in the medium.

So the answer is A

Yes sir I marked that

And it was wrong?

answer (official) given to be B for some reason

the solution (unofficial) makes no sense to me

Can you post the solution?

hopefully its visible

they also gave another "alternative" solution (unofficial) with dimensional analysis

Ah, OK, I see how that works.

What they are saying is that the energy of the blast wave increases the temperature of the air. And the speed of sound varies with temperature.

the V = 4/3pi r^3 step isnt justified right?

ohh

So the speed that the wave travels depends on distance from the blast.

they are saying until wherever wave's reached already are at one temperature and the rest are in other?

Yes.

I dont know how we'd infer that from the question

before seeing the solution

Thank you sir

@RishiNandhaVanchi I would have got it wrong too :-)

:-)

Since lead is almost pure $a_{Pb}$=1 as far as given

However I do not understand how they calculated activities..

@user586228 are you using this book for JEE preparation?

looks like the notation used arent common in jee (or related) exams, you might need to get used to new notation later

I solved by taking RdV/V = CvdT/T

and got B

but apparently this question was deleted for some reason. So B isnt right?

@user586228 The heat equation and the wave equation are parabolic and hyperbolic respectively because...

...because they satisfy the conditions for a PDE to be parabolic and hyperbolic respectively, which in turn is similar to the conditions on the cofficients of a general conic to be a hyperbola or a parabola. See this or the wiki pages mentioned above for details.

@RishiNandhaVanchi No I am already a graduate engineer :-)

@user586228 Can you help with a mechanics question?

Not really ..I am a non IITian

Oh ok, it looks easy though

@JohnRennie Sir, please help when you are free

A body of weight w is lying at rest on a rough horizontal surface. If the angle of friction is θ, then the minimum force required to move the body along the surface will be:

Shouldn't the answer be W*tan(theta)

@JohnRennie There was a question where it asked to calculate the magnetic moment per atom wherein the saturation magnetization was given ...I calculated using my own process only to find out that the answer needs to be divided by 9.27*10^-24..