September 16th 2009ObjectivesHP: SWBAT calculate operations to the correct significant figure.HP: SWBAT express numbers in both standard form and scientific notation.HP: SWBAT apply dimensional analysis to convert units and solve problems.ALL: SWBAT list SI units of measurement and common SI prefixes.ALL: SWBAT calculate the density of a material from experimental data.

Warm Up Wednesday 9/16/2009

Put the following numbers in scientific notation:

a) 12,300.0

b) 0.000345

c) 62,300,000,000,000,000,000,000

What do the following prefixes mean? Example?

a)deci- b) centi- c) mili- d)kilo-

Does coke float in water? Does diet coke float? Does hope float? Why? Or Why not?

What SI units do we use to measure mass, volume, density?

SI Units: The International System

Prefix Chart

Dimensional Analysis: Your friendWhat is it?

- a way to problem-solve that uses the units that are part of a measurement to solve the problem.

What do we need?

-conversion factors that are ratios (fractions) that are equivalent to convert a quantity of one unit to another.

Examples of conversion factors1 pair = 2 shoes, so: 1 pair or 2 shoes

2 shoes 1 pair

1 foot = 12 inches, so: 1 ft or 12 in

12 in 1 ft

Or:

SI Unit Conversions

You write:

1m = 100cm = 1000mm

1L = 1000ml

1g = 1000mg

1kg = 1000g

Let’s Convert

If I have 5.0kg of butter, how many grams is that?

If I drink half (.5) liter of diet coke, how many mL is that?

If I eat 500mg of aspirin, how grams did I consume? How many kg did I ingest?

Density is your Destiny

What is it? -The ratio of the mass of an object to its volume,

Density is substance specific, meaning it won’t change depending on the size. It only matters what it is, not how big or how much. This is known as an intensive property.

Ex. Any amount of water always has a density of 1 g/ml = 1g/cm^3

Density = Mass Volume Units =

Grams or gml cm^3

The Density Pyramid

m

D V

D = m/V V = m/D m = DV

The less dense you are, the further you’ll go…Diet coke is less dense than water, so it floats.

Coke is more dense than water, so it sinks.

Will diet coke float in coke?

Corn Syrup 1.38 g/cm3

Water1.00 g/cm3

Corn Oil0.90 g/cm3

Glycerin1.28 g/cm3

Air\

Homework

1. Bring your Lab Notebook2. Complete Density Work Sheet3. Textbook (HP) R68 #1 (all) #2 a-d, #3 a-d

(textbook in homework section) NEVERMIND

Get my signature for classwork so that you can move on to A+credit before folder time Friday.