Hello,

can anybody tell me how much value is the red line (point on x axis) is indicating in the figure attached?
its confusing me.

thanks

 

It looks to me like the line is about half way between \( 1X10^{^{-4}}\) and \(2X10^{^{-4}}\) . Since on a log chart, half way is about 3, not 5 (i.e., 10^1/2 =3.16...), I would say the line is \(1.3X10^{^{-4}}\).

What is the "correct" answer?

John

 

i thought it was 9.5*10^-3

so, what is it for sure?

 

I thought it was homework. The chart reads left to right, the value has to be less than 10^-3.

John

Edit: If you can find an old slide rule at a museum, you can see what I mean.

 

It looks to me like the line is about half way between \( 1X10^{^{-4}}\) and \(2X10^{^{-4}}\) . Since on a log chart, half way is about 3, not 5 (i.e., 10^1/2 =3.16...), I would say the line is \(1.3X10^{^{-4}}\).

What is the "correct" answer?

Your's is. One could quibble over the last significant figure, but I agree with your estimate.

 

Well, since the mark was in crayon, I didn't try to be too accurate. Besides, it is not often today that you can go back to your old Pickett skills.

In reality, my intent was to help the TS analyze the question.

John

 

So it is somewhere between 0.0001 and 0.001
The next mark to the right represents 0.0002
Hence it is somewhere between 0.0001 and 0.0002

Now look at a slide rule which uses a log scale:

The cursor is positioned halfway between 0.0001 and 0.0002
Hence I call it 0.0001414

Virtual Slide Rule

 

I must have been asleep earlier. The range to consider here is not 1 to 10, but rather 1 to 2. I agree the answer is 1.4142... for the half way point.
John

 

I saw it as not quite halfway, hence 1.3. But upon further review, it is indeed halfway. 1.4 it is.

 

thank guys

ans = 1.414*10^3

 

thank guys

ans = 1.414*10^3

That exponent cannot be right based on the image you posted. Is there more to that image?

John

 

oh sorry, i meant

ans = 1.414*10^4

no there is nothing more to the image

 

Four significant figures? Your eyes must be better than mine.

 

The value exactly halfway (as discussed above) between 1 and 2 is 2^1/2 . My earlier error was a brain lapse, and I was considering the range between 1 and 10.

John

 

Yes, but "exactly" is judged by eyeing a crayon mark, and that judgement doesn't warrant 4 sig figs.