Discuss with your neighbor about your lab

• What did you determine about the relationship between Temperature and Reaction rate?

• Why did you design your experiment the way you did?

• What would you change in the future?

Who will be the winner?? Who can most accurately determine the

density of the metal?

If there are 6 pickles on Every Cheeseburger how many

pickles are there on 4 million cheese burgers?

Relationships are used to solve problems such as these

• 4 million cheeseburgers 6 pickeles

1 Cheeseburger

–Always start with what you have

–End with what you want

–Cancel items in the numerator and denominator

Goody bags are being created for the Eastlake football team. There are 60 guys on the team and each

goody bag costs $2. If candy bars are selling for 3/$1 how many

candy bars should the cheerleaders buy?

• 60 bags $2 3 candy bars

1 bag $1

relationships with measurements relationships with measurements are called Conversion Factorsare called Conversion Factors

Fractions in which the numerator and Fractions in which the numerator and denominator are EQUAL quantities expressed denominator are EQUAL quantities expressed in different unitsin different units

Example: 1 in. = 2.54 cm

Factors: 1 in. and 2.54 cm 2.54 cm 1 in.

How many minutes are in 2.5 hours?

Conversion factor

2.5 hr x 2.5 hr x 60 min 60 min = 150 min = 150 min

1 hr1 hr

cancel

By using dimensional analysis / factor-label method, By using dimensional analysis / factor-label method, the UNITS ensure that you have the conversion right the UNITS ensure that you have the conversion right side up, and the UNITS are calculated as well as the side up, and the UNITS are calculated as well as the

numbers!numbers!

Learning Check

Write conversion factors that relate each of Write conversion factors that relate each of the following pairs of units:the following pairs of units:

1. Liters and mL1. Liters and mL

2. Hours and minutes2. Hours and minutes

3. Meters and kilometers3. Meters and kilometers

Steps to Problem SolvingSteps to Problem Solving

Read problemRead problem Identify data Identify data Identify “what you have” and what you wantIdentify “what you have” and what you want Select conversion factorsSelect conversion factors Change initial unit to desired unitChange initial unit to desired unit Cancel units and checkCancel units and check Do math on calculator Do math on calculator Give an answer using significant figuresGive an answer using significant figures

Learning Check

A rattlesnake is 2.44 m long. How A rattlesnake is 2.44 m long. How long is the snake in cm?long is the snake in cm?

Set up problem then answerSet up problem then answer

a) a) 2440 cm2440 cm

b)b) 244 cm244 cm

c)c) 24.4 cm24.4 cm

Learning Check

How many seconds are in 1.4 days?

Unit plan: days hr min seconds

1.4 days x 24 hr x ?? 1 day

English and Metric English and Metric ConversionsConversions

• You should You should knowknow how to use how to use these conversions:these conversions:

–Mass: 454 grams = 1 poundMass: 454 grams = 1 pound

–Length: 2.54 cm = 1 inchLength: 2.54 cm = 1 inch

–Volume: 0.946 L = 1 quartVolume: 0.946 L = 1 quart

Learning CheckLearning Check

An adult human has 4.65 L of blood. How An adult human has 4.65 L of blood. How many gallons of blood is that?many gallons of blood is that?

Unit plan: L qt gallon

Equalities: 1 quart = 0.946 L

1 gallon = 4 quarts

Your Setup:

SolutionSolution

Unit planUnit plan:: L qt gallon L qt gallon

Setup: Setup:

4.65 L x 4.65 L x 1 qt 1 qt x x 1 gal 1 gal = 1.23 gal = 1.23 gal

0.946 L 4 qt 0.946 L 4 qt

Dealing with Two UnitsDealing with Two Units

If your pace on a treadmill is 65 meters If your pace on a treadmill is 65 meters per minute, how many seconds will it per minute, how many seconds will it take for you to walk a distance of 8450 take for you to walk a distance of 8450 feet?feet?

What about Square and Cubic What about Square and Cubic units? units?

• Use the conversion factors you already Use the conversion factors you already know, but when you square or cube the know, but when you square or cube the unit, don’t forget to cube the number unit, don’t forget to cube the number also!also!

• Best way: Square or cube the ENITRE Best way: Square or cube the ENITRE conversion factorconversion factor

• Example: Convert 4.3 cmExample: Convert 4.3 cm33 to mm to mm33

4.3 cm4.3 cm33 10 mm 10 mm 33

1 cm 1 cm ( ) =

4.3 cm4.3 cm33 10 1033 mm mm33

1133 cm cm33

= 4300 mm3

Learning CheckLearning Check

• A Nalgene water A Nalgene water bottle holds 1000 bottle holds 1000 cmcm33 of dihydrogen of dihydrogen monoxide monoxide (DHMO). How (DHMO). How many cubic many cubic decimeters is decimeters is that?that?

SolutionSolution

1000 cm1000 cm33 1 dm 1 dm 33

10 cm10 cm( ) = 1 dm= 1 dm33

So, a dmSo, a dm33 is the same as a Liter ! is the same as a Liter !

A cmA cm33 is the same as a milliliter. is the same as a milliliter.