Density and Graphing

The Density of an object is it's mass divided by its volume.

d= m/v. and is usually expressed in kg/L, kg/m3, or g/cm3

Ex: d=m/v
       d=135/65
       d= 2.1

Graphing

All graphs must contain 5 important things:
1) Labelled Axis
2)Appropriate Scale
3)Title
4) Data Points
5) Line of Best Fit

To find the slope: m= rise/ run
To find the Area, you must make it into a shape and use the formula of the shape to find the area and add them all up.

-Candace

Dimensional Analysis

There are only 4 steps to converting:
1) Identify what units you want to end up with
2)Find the conversion factors
3) Place units in the appropriate places
4) Cancel units

For example:

? miles = 120 km
120km * 1 mile/1.6 km= 75 mile

 http://www.youtube.com/watch?v=aZ3J60GYo6U

-Candace

Significant digits and Scientific Notation

How we determine what digits are significant:

-all numbers other than 0 are significant

-if the 0 comes after 4 the decimal

·         341----------------> 3

·         41.002 -----------------> 5

·         0.00110 -------------------> 3

-when we add or subtract two numbers we determine the number of significant digits in the answer by rounding the lowest number of significant digits in the initial number.

-When we multiply or divide two numbers we determine the number of significant digits by rounding the lowest significant digits.

-Round only original numbers.

250,000,000 = 2.5x10(8)

0.00940 = 9.4x10(-3)

7,700,000,000,000 = 7.7x10(12)

0.000,000,000,85 = 8.5x10(-10)  

2.57x10(4) = 25700

1.5x10(-5) = 0.000015

8.11x10(7) = 81100000

3.50x10(-3) = 0.00350

What is wrong with writing 25.10(8)?

You cannot have a two-digit number in the front.

2.58x10(8)

-Reo