Graphing and Density

On September 30 we learned about graphing and density.
The density formula being

                    or 

An example of how one might use this formula is say there was a person who wanted to find out their density (for whatever reason). The said person determined that they weighed 47 kg and took up 22L.
Thus to find the density you simple divide the mass by volume, which is 47kg/22L equaling 2.1 kg/L. (Remember your significant digits)


See with chemistry you can not only figure out what clouds are made of but also what the density of clouds compared to the air is.

We also went over graphing.
Graph can be used for 3 things
Examining the graph
Finding the slope
Finding the area

There are also five essential things needed in a graph
labeled axis
appropriate scale
title
data points
line of best fit (this can also become a curve of best fit)

For example

However in this graph due to the angles there is more than one line of best fit.

First off we will find out the slope, the formula for slope being
the slope for 0-2 s is 2/2 =1m/s
2-3 is 0/1=0m/s
3-4 is -2/1=-2m/s
With this information you could also figure out the average velocity but since we didn't go over that today I will simply give you the formula so that if you want you can figure it out yourself. The formula is

Now in order to find the area of the graph you need to take a few more steps, as shown in the graph below.

As you can see the graph is divided into 4 different sections A,B,C and D
note how the sections go right down to the x-axis. Once you have your sections separated you find the area of each using the appropriate formulas in this case you would use A=(l)(w) for A and C, you would use A= 1/2 (b)(h)
for B and D.

To show and example in order to find the area of a here's what you do

A=(l)(w)  B=1/2(b)(h)   C= (l)(w)
   =(4)(1)    = 1/2(2)(2)     =(1)(2)
   =4           = 4                  = 2
D=1/2(b)(h)
   =1/2(1)(2)
   =1
Thus the area would be11(m)(s)

Which is what we learned on Sept. 30 in a nutshell.