Ch 1 toolkit
2010-2011
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Welcome!
Introductions
Egg mobiles
HW: Due Friday
Agenda 9/8
– return signed lab safety
agreement
– Buy a notebook and get a
calculator
– Book?
• Objectives:
• Clarify and
communicate class
procedures and
policies
• Introduce inquiry
method of
investigating
science
Agenda 9/13 Physics
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Pick up textbooks in library
Go over guided outline and homework
Drop eggmobiles/lab report Due tomorrow
Go over dimensional analysis
Introductions
– Stand Up – Silently move around the room and
greet each other
– Hand up – partner up with the person closest to
you
– 30 seconds – tallest person share your dream
vacation – switch
– 30 seconds – shortest hair share your favorite
meal
– 30 seconds – biggest feet share why you are taking
this class
Egg mobile Project
• Directions
• The directions can be found on my website in
ch1 assignments
Scavenger hunt
1. Where is the eyewash
station?
2. Where can you find
copies of old handouts?
3. Where can you find
loaner pencils?
4. Where can you find
extra paper?
5. Where is the tissue?
6. What are Burkhart’s 3
rules?
7. Where is the closest
toilet?
8. Where are the loaner
rulers?
9. When can you take a
“green” physics book
out of this room?
10. What is the coolest club
on campus?
Match game
• In groups of 4
• Match the item to the correct SI unit of
measure
second, kilogram, Kelvin, meter, coulomb,
Prefix contest
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teams of 7
Metric prefixes are on a set of index cards
Each team member gets a card
Teams race to see which team can line up in
order from largest to smallest
dfa
• How many meters are in 3.0 km?
• How many Curies are in 900 pC?
LAB REPORT
• Title
• Purpose in own words
• Data in a neat table
• Graph
• Your prediction in a
complete sentence
• Answer Q 5
9/15/10 physics agenda!
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Do Now and Calendar
Check homework go over
Scientific notation and your calculator
Metrics conversions ez
Sig figs , rounding
Math with sig fig
Scientific Notation
• Sometimes we will be working with
really big or really small numbers
• i.e. 602200000000000000000000
• .0000000000000000001602 J
Scientific Notation
• It is cumbersome to deal with these
ridiculous numbers
• We use “scientific notation” to make
big/small number manageable
Scientific Notation
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We don’t lose any significant digits
602200000000000000000000
becomes 6.022 x 1023
.0000000000000000001602 J
becomes 1.602 x 10-19 J
M x 10Exp M is between 1 and 10
Scientific Notation
• Move the decimal until only one non
zero digit remains on the left
• Count the number of places the
decimal was moved - that number is
the exponent of “10”
• Note : the exponent becomes larger
as decimal moves to left
Metric Prefixes
• Prefixes are used to change SI units
by a power of ten
• pico, nano, micro, milli, centi, kilo,
and mega are common prefixes we
will use - memorize them
The key concept of dimensional
analysis
• Showing conversion factors
• 1 dozen = 12 eggs
Conversions are shown as a fraction
1 dozen
12 eggs
Often the conversion factors show the relationship
between 1 of a unit to a certain number of
another unit (example 12 eggs in a dozen eggs)
Copy this into your book next to your
sig fig rules.
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G
Giga
1x 109
M
Mega
1x 10⁶
k
kilo
1x 10³
base unit unit only(g,m,l) (1 x 100 ) add this
d
deci
1 x 10⁻¹
c
centi
1x 10⁻²
m
milli
1x 10⁻³
µ
micro
1x 10⁻⁶
n
nano
1x 10⁻⁹
p
pico
1x 10⁻¹²
ƒ
femto
1x 10⁻¹⁵
The method for metric conversions:
A. Set up your problem for dimensional analysis
you want to know how many grams are in 3340 mg
? g = 3340mg
B. Use the prefix table to determine the absolute
difference in exponents .
For example g to mg 100 to 10-3 the difference is 3
which becomes 1x103
C. Set up your conversion by putting the BIG number
with the LITTLE unit!
? g = 3340mg .
____1___g = 3.34
1 x 103 mg
What about sig figs you ask? Make sure your answer has
the same as the number you were given
Practice
SHOW YOUR WORK AND UNITS!
CIRCLE OR ENCLOSE YOUR ANSWER WITH UNITS
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6.
7.
98.4g to mg
45.3 µm to mm
6.4 x 105nm to m
155.0 L to mL
250.6 µg to kg
1.109 x 10-4 kg to mg
5.07 x 1010cm to km
Significant Digits
• Rules for significant digits in a
measurement
• all non zero digits are significant
• zeroes in between two sig figs are
significant
• zeroes at the end of a measurement are
sig
• all other zeroes are not significant (place
holders)
Significant Digits
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Examples
3.01 m
3.0100 cm
93,000,000 miles
3000 kg
3001 kg
rounding
• If the number you are rounding ends in
• 0-4 just drop
• 5 exactly then
– drop if the number to the left is even
– round up if the number to the left is odd
• More then exactly 5 up to 9 round up
Significant Digits
• Rules for significant digits in calculations
• multiplying and dividing: answer can only
have as many digits as the product (divisor)
with the least amount of digits
• Adding / subtracting – your answer is limited
by the least accurate number (least decimal
places ) that you are adding together
Significant Digits
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Examples
0.4356 m x 34.2 m
87.3 cm x 44.23 cm x 3.1 cm
23.9 g / 24.01 cc
133.4 kg + 44.98 kg + 3.9 kg