@Abcd to be honest I wish I'd just drawn a diagram like the one above for that question.

Isn't it obvious from the diagram why the reading is 28.3? No messing around with MSDs or whatever.

nope its not obvious to me

@JohnRennie why move left??

@Abcd If you start with the calipers closed then the zero on the main scale and the zero on the vernier scale are aligned. Yes?

@JohnRennie yes

Now you put some object with a size $D$ in the jaws. That means the movable jaw has to move a distance $D$ to the right.

The vernier scale is written on the movable jaw, so that means the whole vernier scale moves a distance $D$ to the right along with the movable jaw.

OK so far?

@JohnRennie yeah

So the zero on the vernier scale is now at a distance $D$ on the main scale.

@JohnRennie agree

We can see that $D > 28$ and $D < 29$ but we can't be any more precise than that because the main scale is only marked in 1 mm steps.

But we know that 7 on the vernier scale lines up with 36 on the main scale.

@JohnRennie ya

And we know the vernier spacing is 1.1mm

So that means $D + 7.7 = 36$

@JohnRennie Wow!!

@Abcd Yes :-)

It really is as simple as that!

Why do people like to complicate stuff

@Abcd now you see why I wish I had drawn this diagram earlier. I just didn't think of doing it.

If the limiting value of $\mu$ friction coefficient for a block to topple and slide is same, what will happen first, tippling or sliding?

@PolarBear call the limiting value $\mu_0$. Now if you have $\mu > \mu_0$ the block topples. If you start with large $\mu$ and then see what happens as you reduce $\mu$ the block always topples.

If you have $\mu < \mu_0$ the block slides. So start with small $\mu$ and increase it towards $\mu_0$ and the block always slides.

So what happens at $\mu_0$ depends on which direction you approach from. That means the behaviour at $\mu_0$ is not defined.

@JohnRennie Ahha, I get it. In the question it's the former case. But why?

@PolarBear I'd have to see the question

Oh wait, got it.

What you said is correct

The question's a bit long though and the question finally boils down to what I asked

I missed that the question said it was always greater than $\mu_0$

Thank you for pointing it out because I forgot.

@JohnRennie Can you please explain what does $\dfrac{dN u}{N du}$ exactly mean in Maxwell's distribution curve

@JohnRennie Are you there?

@AdvilSell ^^^^

@Abcd ah..I can't explain it ! sorry

@AdvilSell do you know what it is??

@Abcd Sorta , But surely I can't explain it

@AdvilSell k

@Abcd Maxwell distribution?

@JohnRennie chem.libretexts.org/Bookshelves/…

@JohnRennie Maxwell-Boltzmann distribution

@JohnRennie instead of probability on Y axis my book has dNu/Ndu

@Abcd can you post a picture?

@JohnRennie yes

@Abcd I have to admit I don't understand what that means.

@JohnRennie Okay

@Abcd Given briefly in Opt about the deferential expression.

Physics exam tommorow :(

@amanuel2 All the best man :D

Thanks :)

About to review a lot so I might ask some question to the physics whiz's @tatan and @JohnRennie ;)