Dimensional Analysis

- Just like converting between currencies in chemistry it is usually necessary to convert between units
- This process is called Dimensional Analysis

Steps
1. find a unit quality
2. find the conversion factors
3. apply conversion factors
4. cancel units

example
http://upload.wikimedia.org/math/b/e/4/be413a0d3340a3ec49906113fb96ac61.png
                                           

SCIENTIFIC NOTATION VIDEO :)
http://www.youtube.com/watch?v=H578qUeoBC0

SIGNIFICANT DIGITS:


If a digit is not 0, it's always significant 
If the zero is a "place keeper" it's generally not significant ex: >0.0042
Any number to the right of a decimal point are significant if they come after a non-zero number 
ex: >4.60 is 3 digits significant because it starts at 4
      >2.0 is 2 digits because it starts at 2
      >0.0035 is 2 digits because it starts at 3
When adding or subtracting, round to the least precise number ex: >7. 4212
                                                                                                      -3. 5400   
                                                                                                       3. 8812= 3.88 [ both the tenths and  hundredths value have the same value so you round it to the nearest hundredths] 
                                                                                                     > 12. 300
                                                                                                      +10. 771
                                                                                                         23. 071= 23.1 [ the smallest value is in the tenths place so you round it to the nearest tenths]


When you multiply or divide, round to the number with the fewest S.D.S ex: >2. 5 x 5. 55= 13. 875=14 
                                                                                                                    >1. 33421 x 19. 531=26. 0584551= 26.058


SCIENTIFIC NOTATION:


Shows really big or small numbers make use power of 10 ex: >10^5=100000
                                                                                             >12300000= 1.23 x 10^7
                                                                                             >0. 00000342 x 10^-6
                                                                                             >0. 0000002.97 x 10^-7 


CALCULATORS: Your calculator has functions that you can use to do this easily 
                                 [for graphing calculator models of ti-83 or newer]: 
                                 PRESS: EXP
                                               EC
                                               X 10
                                               S.N.
DO NOT USE " ^ " ON YOUR CALCULATOR FOR YOUR CHOSEN EXPONENTS 


*WELL FOLKS THAT WRAPS OUR DAILY BLOG ON  SIGNIFICANT DIGITS AND SCIENTIFIC NOTATION, HOPE YOU CHECK OUT OUR NEXT BLOG SO YOU CAN SEE WHAT NEW STUFF WE HAVE IN STORE FOR YOU, CHEERS!!! :)

POWERS OF TEN... the unimaginable size of our universe

SI System + Percent Error

Prefixes are essential to change the power of a number
Tera 10^12
Giga 10^9
Mega 10^6
Kilo 10^3
Hecto 10^2
Deca 10 ^1
Deci 10 ^-1
Centri 10^-2
Milli 10^-3
Mirco10^-5
nano 10^-9
Pico 10^-12
Femto^-15
We see prefixes everyday to represent VERY LARGE or VERY SMALL numbers
For example...

32 MEGA(10^6) byte of memory meaning 3.200,000 bytes of memory!!!  Want to see the POWERS OF POWERS!?!?!Here we go (:Keep on reading this blog to watch the video (: its on the next post  
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Experimental Acurracy
Maximum accuracy of any measurement is 1/2 of the smalles division of a measuring device
 For example :) odometer in a car has a maximum accuracy
of +/- 50 m

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  ERROR D:
There are 3 reasons of error (even though we will get error in measuring almost all the time -.-)
1)Physical errors in the measuring device
2)Sloppy measuring
3)Changing ambient conditions

Luckly, I guess, there are ways to calculate how wrong you are.

1) Absolute Error:
AE= Measure-Accepted
Positive number as a result means it is over the accepted value
Negative number as a result means...its the end of the world. No, it means it is under the accepted value (unless the result is 2012...then you freak out)

2)Percent Error
It can simply be calculated like this:
%Error= (Measured-Accepted/Accepted) x100
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Well thats the end of this summary of this lesson stay tuned next time when we learn about SIGNIFICANT DIGITS AND SCIENTIFIC NOTATION :D