@PrateekMourya in general a mixture of two ideal gases will also be ideal.

We consider a gas ideal if its molecules only interact weakly with each other, and if you have two gases both of which interact weakly it is very likely their mixture will interact weakly as well.

Ok sir

@JohnRennie hi

@Anusha hi :-)

U free?

@JohnRennie

Is it quick? My lunch will be ready in 10 minutes.

Yup

OK, then I'm free :-)

I dont find any argument justifying the first statement

It's a very strange question. It says the walls are adiabatic so I guess that means they don't conduct heat. That means neither of the spheres should lose any heat to the walls.

i.e. the whole interior of the chamber should be at the same temperature.

So I cannot see how (A) can be true.

And (B) is just a restatement of dU = dQ - dW as far as I can see.

I agree to that my sir said that maybe adiabatic here means that heat is not escaping from system and as 1 has an extra area of contact it has absorbed more heat but does it seem relevant?

And (C) seems just to be saying that if you treat the spheres the same way they will behave the same way.

@Anusha I think you could argue it both ways. It's just a really badly phrased question.

Ok then thnx

You could argue that the walls will be at the same temprrature as the spheres anyway

Because everything in the chamber is being heated by the hot air from the heating element.

Hello @JohnRennie sir

@PrateekMourya hi :-)

Sir question is a beam of nitrogen moving at speed 400m/s

Stirkes wall at 30° angle

Find pressure on wall

Are you comfortable to answer now?

Yes, this is simpler than you think.

The force on the wall is just the rate of change of momentum of the nitrogen atoms.

Yes

Only the component of the momentum normal to the wall is changing, so specifically it is the rate of change of the component of the momentum normal to the wall.

Yes

One more thing

Yes ... ?

Molecule per unit volume is also given

They do that because they are asking for the pressure i.e. the force per unit area of the wall.

So you need to calculate how many nitrogen atoms per second per unit area hit the wall. That's why they are telling you how far apart the nitrogen toms are spaced.

A parallel beam of nitrogen molecules moving with velocity v = 400 m/s impinges on a wall at an angle θ = 30° to its normal. The concentration of molecules in the beam n = 0.9.1019 cm-3. Find the pressure exerted by the beam on the wall assuming the molecules to scatter in accordance with the perfectly elastic collision lawRead more on Sarthaks.com - sarthaks.com/209996/…

I try solving using considering a cube around the heating area

And then using some of the methods of deriving the ideal gas equation

To estimate the force

Methods used in this derivation

Let's do this tomorrow morning. It's nearing the end of my day now.

Ok

@Anusha prnt.sc/wpymxb

I think it was in some sort of olympiad, this problem.

@Anusha arxiv.org/pdf/1502.01337.pdf

this is the solution of this problem I saw it somewhere but I have forgotten.