Significant Figures

[Xylitol]

So I'm studying physics and we have to learn about sig figs... and I dont' get wtf they are
Can someone quicly explain to me in cliffs?

(Exam tommrow)

 

[Juice Box]

its how detailed your answer should be.

either number of 0's after the decimal or before...you base it off of the numbers they give you

 

[YOyoYOhowsDAjello]

Do you just need to identify how many sig figs something has... or do you need to know how to carry sig figs through calculations?

 

[ajpa123]

I thought this thread was gonna have links to hot chics

 

[Xylitol]

Like the questinosn prof. said was that
he'd sort of give numbers of measurement
and we have to average it to the righ amound of sig figs... and i dont' get wth is going on in this class

 

[YOyoYOhowsDAjello]

Originally posted by: Xylitol
Like the questinosn prof. said was that
he'd sort of give numbers of measurement
and we have to average it to the righ amound of sig figs... and i dont' get wth is going on in this class

Is this a college class?

Do you know anything about significant figures?

(Like would we need to show you how you figure out how many sig figs something has, or do you know that already?)

 

[klah]

http://www.physics.uoguelph.ca/tutorials/sig_fig/SIG_dig.htm

 

[SNiPeRX]

simple

take 000.0033231

The number of significant figures are 6. Anything after the zeros are significant. In cases where the decimial is after the sig figs you count those as well.

take 1,345,000.00 the significant figure is 9.

 

[hjo3]

300 <- 1 sig fig
3.00 <- 3 sig figs
3.01 x 10^2 <- 3 sig figs

 

[YOyoYOhowsDAjello]

Test:

How many sig figs?

a) 10000
b) 34200
c) 77.00
d) 0.00034
e) 12.00055
f) 2.120030
g) 6.023 x 10 ^ 23
h) 3.00 x 10 ^ -3

 

[DaveSimmons]

Assuming this isn't some wacky difference between physics and math:

consider this:

0.123456

and this

0.0000000000123456

once you normalize the second number by increasing the negative exponent they really have the same number of significant figures / digits (6).

If you were adding either of those with say 0.222 e-N then

* 1 significant figure would be 0.3 e-N
* 2 would be 0.34 e-N

At least in math it's talking about the biggest part of the number, regardless of the exponent.

 

[hjo3]

Originally posted by: SNiPeRX
simple

take 000.0033231

The number of significant figures are 6.

Uhh... no, that's 5 sig figs.

 

[YOyoYOhowsDAjello]

Originally posted by: hjo3

Originally posted by: SNiPeRX
simple

take 000.0033231

The number of significant figures are 6.

Uhh... no, that's 7 sig figs.

uhhh.... 5?

 

[hjo3]

Originally posted by: YOyoYOhowsDAjello

Originally posted by: hjo3

Originally posted by: SNiPeRX
simple

take 000.0033231

The number of significant figures are 6.

Uhh... no, that's 7 sig figs.

uhhh.... 5?

Typo.

 

[YOyoYOhowsDAjello]

Run Xylitol, this thread will only destroy you.

Go on a google search and figure it out.

 

[SNiPeRX]

I put one to many numbers on the first example... sorry. Atleast u know I dont copy and paste like others.

 

[Xycl0ne]

Originally posted by: YOyoYOhowsDAjello
Run Xylitol, this thread will only destroy you.

QFT. Significant digits aren't too hard, just use teh Google. :thumbsup:

 

[YOyoYOhowsDAjello]

Originally posted by: SNiPeRX
I put one to many numbers on the first example... sorry. Atleast u know I dont copy and paste like others.

I made my test up. I'm waiting for him to try it, but I think this thread may just confuse him more.

Hopefully this is just identifying sig figs. In my Physics 307 lab we were going Standard devations and calculating sig figs for differentiation and integration etc. (not fun)

 

[SNiPeRX]

I hated math in college, but for some strange reason I remembered this crap. I guess I did remember some stuff.

 

[Xylitol]

Hmmm... lets see the test...
I'll edit when i get all of em

Edit:
a.1
b.3
c.4
d.5
e.7
f.7
g.4
h.5

(This better be right )

 

[YOyoYOhowsDAjello]

Originally posted by: YOyoYOhowsDAjello
Test:

How many sig figs?

a) 1
b) 3
c) 4
d) 2
e) 7
f) 7
g) 4
h) 3

I think I got my own test right

Looks like H and D are not the same answers

 

[hjo3]

Originally posted by: Xylitol
Hmmm... lets see the test...
I'll edit when i get all of em

Edit:
a.1 - yep
b.3 - yep
c.4 - yep
d.5 - nope
e.7 - yep
f.7 - yep
g.4 - yep
h.5 - nope

(This better be right )

.

 

[YOyoYOhowsDAjello]

d) 0.00034

Only the last two are significant digits.

The zeros ahead of the three just indicate the magnitude of the answer.

zeros after a decimal point are only significant if there is a non-zero number before them

1.0000

= 5

1.0001

= 5

0.0100

= 3

0.00010

= 2

0.0010010

= 5

 

[YOyoYOhowsDAjello]

h) 3.00 x 10 ^ -3

Scientific notation is pretty easy once you see you don't really have to think about it.

Unless he's trying to trick you with notation that looks like Scientific Notation and really isn't, you just need to count the digits in the part before the "x"

1.23456 x 10 ^ 1347932143196491792794

= 6


4.50100 x 10 ^ eleventybillion

= 6


This would be a trick one

12400 x 10 ^ 23

= 3 (no decimal point in the original number... I've seen this given on tests)

 

[Xylitol]

d' oh
Imma screw up
O well thx guys