ORGANIZED APPROACH TO PROBLEM SOLVING USING UNITS

Factor Label/ Conversions/ Dimensional Analysis

3 QUESTIONS TO ANSWER

1. What unit do you need?

2. What information is given?

3. What conversion factors do you need?

CONVERSION FACTOR:

CONVERSION BETWEEN 1 UNIT AND ANOTHER; ANY TWO THINGS THAT ARE EQUAL.

EX: 16 oz. = 1 lb 1 km = 1000 M 1.06 qt = 1 L

Look at the example:

Ex: ? cm are there in 30 ft?

?cm = 30 ft 12 in 2.54 cm = 914.4 cm 1 1 ft 1 in

What pattern do you notice?

1. ALWAYS START WITH "? units wanted”

? Units wanted =

2. Write Given quantity on top

? Units wanted =

Given quantity

3. Write matching conversion factor on bottom of next parenthesis

? Units wanted =

Given quantity

Matching conversion factor

4. Put wanted unit of conversion factor on top!

? Units wanted =

Given quantity

Matching conversion factor

Wanted unit of conversion factor

5. Multiply everything on top, and divide by everything on bottom!

? Units wanted =

Given quantity

Matching conversion factor

Wanted unit of conversion factor

*In calculator type: (multiply everything on top) / (multiply everything on bottom) = your answer with units wanted!

? Units wanted =

given quantity

Units wanted

Matching conversion factor: MUST be in SAME UNIT as your Given Quantity!!!!!!!!!!

*You must have the same unit on top in the first parenthesis, as you do in the bottom of the next parenthesis!!

*Diagonal Units: must cancel out!

•You can also do this with multiple conversion factors!

? Units wanted =

Given quantity

Matching conversion

factor

Some unit

•Start with same steps as before, but your first conversion factor may not have the wanted unit on top.• You may need to use many conversion factors to get to the unit wanted!!

Some unit conversion

factor

Units wanted!

Always make sure that diagonal units cancel out!!!

Lets do some examples!!!!!!!!!

Example Problems:1. ? Seconds has a 16 year old lived2. ? Lbs is a 200,000g sumo wrestler3. ? Warps are there in 9x1012 wags1 wag = 95 zooms 1000 warps = 1 dirg 67 zooms = 1 dirg

4. Jeff drove 2 x 103cm/sec to school, which is 9miles away. How many min did it take to get to school?

12in = 1ft 1in = 2.54cm 5280ft = 1mile

5. Susan drank 32 lbs of soda. If soda has a density of 0.999g/cm3, how many qts did she drink?

1 lb = 454g 1 cm3 = 1 mL 1 qt = 946 mL

SI UNITS: SYSTEME INTERNATIONALE

Base Units:

LENGTH - m - meterMASS - kg - kilogramTIME - s - secondsTEMP - K - KelvinAMOUNT - mole - molecular units

'

SI Units: based on powers of 10--METRIC PREFIXES 106 - M - mega 103 - k - kilo 102 - h - hecto 101 - da - deka

10-1 - d - deci 10-2 - c - centi 10-3 - m - milli 10-6 - - micro 10-9 - n - nano 10-12 - p - pico

- meter

100 - BASE - liter - grams

MANYKIDSHAVEDROPPED OVERDEAD CONVERTINGMETRICS

Now you create your own!!!

METRIC TO METRIC CONVERSION RULES:

1.Write ? Unit looking for

2.Write given quantity on top

3.Use matching conversion factor:

METRIC TO METRIC CONVERSION RULES:

3. Use matching conversion factor:i. Place given unit on bottomii. Place desired unit on topiii.Put a 1 in front of the bigger metric

unitiv.Put a (+) positive power of 10 on

the smaller metric unit

METRIC TO METRIC CONVERSION RULES:

5.Cancel all diagonal units (except for the one you are looking for

6.Multiply everything above the line and divide by everything below the line.

METRIC TO METRIC CONVERSION RULES:

HINTS:1. Go from given unit to base unit2. Go from base unit to unit wanted3. Always use a (+) positive exponent number4. Put the (+) exponent number on the smaller unit

8 km = ______ cm

? cm =

? cm =

8 km = ______ cm

8 km

8 km = ______ cm

? cm = 8 km

1000 m1 km

8 km = ______ cm

? cm =

8 km

1000 m1 km

100 cm

1 m

8 km = ______ cm

? cm =

8 km 1000 m 100 cm 1 km 1 m =

800,000 cm 1

1.? cm are in 5km

2.? ng are in 6.2 x 1012dg

3.? hL are in 5mL?

EXAMPLE OF METRIC TO METRIC CONVERSIONS

METRIC - ENGLISH CONVERSIONS

2.54 cm = 1 inch454 g = 1 lb.1.06 qt. = 1 L 3 1 mL = 1 cm

ENGLISH CONVERSIONS16 oz = 1 pound (lb) 12 in. = 1 ft

3 ft = 1 yd4 qts = 1 gal

5280 ft = 1 mile