# September 16 th 2009 Objectives HP: SWBAT calculate operations to the correct significant figure. HP: SWBAT express numbers in both standard form and scientific.

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September 16 th 2009 Objectives HP: 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 friend What 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 factors 1 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 wont 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 g ml cm^3

The Density Pyramid m D V D = m/VV = m/Dm = 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 Water 1.00 g/cm3 Corn Oil 0.90 g/cm3 Glycerin 1.28 g/cm3 Air\

Homework 1. Bring your Lab Notebook 2. Complete Density Work Sheet 3. 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.

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