Question

Significant figures?! @perl

Answer 1

whats the difference between a measurement of
3.2 meters
versus
3.20 meters

Answer 2

no difference...

Answer 3

oh, i see...I never learned error, etc.

Answer 4

whenever you do a measurement, there is an uncertainty related to the measurement

Answer 5

I've seen people talking about it on OpenStudy, but I've actually never learned it.

Answer 6

ok lets imagine you are looking at a meter ruler

Answer 7

Ok

Answer 8

a measurement of 3.2 meters is to the *nearest* tenth of a meter

Answer 9

a measurement of 3.20 meters is a measurement to the *nearest* hundreth of a meter

Answer 10

Oh, that makes sense...so it is more precise

Answer 11

they indicate different scale precisions

Answer 12

right

Answer 13

there are different conventions people use, i use

Answer 14

I get that. So in the number 0.0050, does it have 4 significant figures, or 2?

Answer 15

that will have 2, since the zeroes in front of the 5 can be removed, they are merely placeholders

Answer 16

I see. Thank you so much @perl

Answer 17

My chemistry lessons didn't go into this much detail.

Answer 18

the rules for sig fig are a little nutty. they are trying to incorporate two themes, precision and scientific notation

Answer 19

lol, "a little nutty"
I'm with you on that

Answer 20

scientific notation is digit.decimal x 10^power

Answer 21

What about this?
1.050?
Wouldn't that be 3, not 4?

Answer 22

that will be 4 , since the last zero indicates precision

Answer 23

what about the first zero?

Answer 24

let me be explicit , i will make a rule

Answer 25

that's what i meant

Answer 26

the first zero in between cannot be removed either,

Answer 27

but isn't the first zero a place holder?

Answer 28

the expression cannot be condensed

Answer 29

well... yes but

Answer 30

but...?
NUTTY

Answer 31

you cant shrink the expression by putting it into scientific notation

Answer 32

one sec, let me give you a rule for measurement error

Answer 33

okay, so it is only ignored as a place holder if it can be gotten rid of through scientific notation

Answer 34

what exactly is the difference between 3.2 and 3.02 meters

Answer 35

...3.2 is 3 and 2 tenths. and 3.02 is 3 and 2 hundreths

Answer 36

for a measurement of 3.2 meters, x can be any number between:
3.2 - .1/2 < x < 3.2 + .1/2

for a measurement of 3.20 meters , x can be any number between
3.20 - .01/2 < x < 3.20 + .01/2

Answer 37

since we are saying, 3.2 is to the 'nearest' tenth of a meter

Answer 38

Yeah. I see

Answer 39

Okay, so 223.0050 has 7 sig figs? and 0.005 has 1 sig fig?

Answer 40

so for 3.2 meters

3.15 < x < 3.25


for 3.20 meters

3.195 < x < 3.205

so you see the precision increases

Answer 41

Okay, so 223.0050 has 7 sig figs? and 0.005 has 1 sig fig? yes and yes

Answer 42

does 200.0500 have 7 sig figs too?

Answer 43

yes,

Answer 44

awesome. I think I get it now. Thank you SO, so much @perl

Answer 45

the zeroes in between 2 and 5 are 'stuck' , cannot be eliminated. and the zeroes at the end after 5 indicate precision

Answer 46

by eliminated i mean with scientific notation

Answer 47

:)