Warm-Up!

1
Warm-Up!

• 1. Match the unit on the left with the value on
  the right.
• a. Milli- 1. 1000x
• b. Kilo - 2. 0.10x
• c. Centi - 3. 0.001x
• d. Deci- 4. 0.01x
• 2. Name the metric unit most appropriate for
  measuring
• A. Mass of a penny d. Volume of Pepsi
• B. Distance to Tahoe e. Your mass
• C. Length of your shoe f. Temperature of your
  coffee
• 3. a) You have a gold ring with a volume of 0.75
  cm3. Given that the density of gold is 19.31
  g/cm3, what is the mass of that gold?
• b) If gold is worth 900 per ounce, how much is
  your ring worth? (0.040 ounce/gram)

2
Test Your Metric Knowledge

• 1. A gram is about the weight of
• (a) _____ an apple
• (b) _____ a dime
• (c) _____ a pineapple
• 2. A meter is about the height of
• (a) _____ a door
• (b) _____ a kitchen counter, or a doorknob
• (c) _____ the seat of a chair
• 3. Water freezes and boils at
• (a) _____ 32 C and 212 C
• (b) _____ 100 C and 200 C
• (c) _____ 0 C and 100 C
• 4. A coffee cup holds about
• (a) _____ 2 milliliters (mL)
• (b) _____ 20 mL
• (c) _____ 250 mL
• 5. A newborn baby weighs about
• (a) _____ 3 kilograms (kg)
• (b) _____ 30 kg

• 6. The height of a tall man is about
• (a) _____ 20 centimeters (cm)
• (b) _____ 200 cm
• (c) _____ 2000 cm
• 7. Normal body temperature is
• (a) _____ 25 C (degrees Celsius)
• (b) _____ 37 C
• (c) _____ 45 C
• 8. A liter of milk is
• (a) _____ larger than a quart
• (b) _____ smaller than a quart
• (c) _____ the same size as a quart
• 9. A liter of water weighs
• (a) _____ 1000 grams (g)
• (b) _____ 20 g
• (c) _____ 100 g
• 10. The thickness of a dime is about
• (a) _____ 0.1 millimeters (mm)
• (b) _____ 1 mm

3
Answers 1. b 2. b 3. c 4. c 5. a 6.
b7. b 8. a 9. a 10. b
4

• Why is measurement important?

5
 

• Units of Measurement 2.1 (pages 25 30)
• A. Why the Metric System?
• National Metric Week Oct. 9 - 15, 2011
• (10th month and the week containing the 10th day)

6
B. Base Units of the SI System
 
Based on an object or event of the physical world
Independent of other units
Quantity Base Unit Abbreviation
Time
Length
Mass
Temperature
Amt of Substance
Electric Current
Luminous Intensity
Second
s
Meter
m
Kilogram
kg
Kelvin
K
Mole
mol
Ampere
A
Candela
cd
7
C. Derived Units
 
Combination
____________________ of base units
ü    Volume cm3 (solids) or ml (liquids)
ü    Density g/cm3 (solids) or g/ml (liquids)
You need your calculator
8
Density Challenge!

• Goal Determine the largest amt of sand that can
  be added to a film canister so that it can still
  float in a container of water.
• What to do
• Obtain a film canister and ruler.
• Calculate total mass needed for floating (water
  has a density of 1 g/cm3)
• Add sand to container to get to obtain desired
  mass
• Bring film canister w/ sand to Ms. Buchanan for
  testing
• If it floats (without tipping over) you get 10
  lab pts!
• You can buy a hint for 2 pts.
• If it sinks or tips, you get 5 pts.
• Highest mass that floats 5 xc points!
• Second highest mass that floats 3 xc points!

9
D. Temperature Scale
Celsius Scale Water Freezes ________   Water
Boils __________
0ºC
100ºC
Kelvin Scale (add 273 to ºCelsius) Water
Freezes_______   Water Boils________
273K
373K
10
II. Scientific Notation Dimensional
Analysis A. Scientific Notation 1. Handling
numbers

• in a gram of Hydrogen there are
  602,214,000,000,000,000,000,000 atoms
• distance between particles in a salt crystal is
  0.000 000 002 814 cm
• add 0.000 000 000 036 0.000 000 000 000 046 ?

Easier to use scientific notation M x 10n M
between 1 10 n integer (1, 2, 3...)
11
Examples (from above)   1) 6.02214x1023 2)
2.814x10-9 3) 3.6x10-11 4.6x10-14 ?  
3.6046 x 10-11
12
Try a few! 4) 6.3x104 3.9x103 ?       5)
(8.0x104) (5.0x102) ?       6) 6.0x107
9.0x105       7) 3.0x10-8 5.0x109
6.69 x 104
4.0 x 107
6.7 x 101


6.0 x 10-18
13
Estimate how far the winning jump was in feet.
14
7.15 m
X
X
X
J. Faklaris
23.5 feet
15

• D. Dimensional Analysis (aka Factor label) p.
  34-35
• Activity Directions
• Table groups, take the cards out of your
  envelope.
• Find the card showing the island and people. How
  many people live on the island?
• Now find a card with a person and a house.
• How many houses are on the island?
• How many dogs are on the island?
• How many cats are on the island?
• How many pine trees are on the island?

16
2. Examples without the cards! a. How many
meters in a one hundred yard dash? 1inch 2.54
cm

91.4m
100 yds
X
? m
X
X
X
17
b. How many kg in a 4.00 ounce McDonald's
hamburger? 1kg 1000g 16 ounces 1 pound 1
pound 454 grams
0.114 kg
18
c. If Shaq is 7'2" tall how many millimeters tall
is he? 1 inch 2.54 cm  
2184 mm
19
d. Convert 8 wags to warps. 1 wag 12 zooms
1000 warps 1bam 3 zoom 1 bam
32,000 warps
20
e. A computer switch switches 60 times in a
microsecond, how many times does it switch in a
minute? 1,000,000 microsecond 1 sec  
3.6 x 109 switches in a minute
21
f. How many milliliters in a 12 fl oz can of
soda? 1000ml 1L, 1L 1.06 quarts, 4 quarts
1 gal, 1gal 128 fluid oz.
354 mL
22
Warm-Up Dimensional Analysis

• Calculate the time required for a student aide to
  earn 567 at 9.00 per hour.
• Answer 63.0 hours
• How many square feet are in 6.60 square yards?
• Answer 59.4 ft2
• Change 15 mph to feet per second.
• Answer 22 feet per second

23
 
III. How Reliable are Measurements? Accuracy vs
Precision
24

•  
• III. How Reliable are Measurements?
• precision how close a series of measurements
  are to one another reliability or
  reproducibility
• Usually reported as /- 1 of the estimated unit
  or by looking at the deviation of the data from
  the mean (absolute, or standard deviation).
• accuracy - how a measured value is to an accepted
  value reported as error
• error observed value - true value x
  100
• true value

25
Practice w/ Measurement

• Everyone write down a measurement for the width
  of your note sheet. Please use centimeters and
  estimate to the nearest 0.05 cm.
• Write down the measurements taken by yourself and
  4 others near you.
• Determine your average measurement (mean).
• Calculate your accuracy ( error) given that the
  True value (according to Ms. B?) is 21.55 cm.
• Now determine your precision. Find the
  /deviation/ of each measurement as compared to
  the mean. Average these deviations. This is
  your /- precision.
• Record as Average /- average deviation.
• Honors Determine Standard Deviation

26
Rules for Significant Figures (sig figs)pgs.
39-42 1. Definition Any number that is
measured   2. zeros that act as place holders
are not significant   ex. 3 cm 0.03 m _____
sig fig   3. All final zeros to the right of
the decimal place and arise as a part of a
measurement are significant ex0.0005030 _____
sig fig ex 600? use scientific
notation   6.00x 102 ______ sig fig 6.0 x
102 _____ sig fig   6 x 102 _____ sig
fig
?Include all known values, plus one estimated
value
1
4
1
3
2
1
27
4. Non-zero measurements are always significant
5. Zeros between non-zero numbers are always
significant
28
  6. At times the answer to a calculation
contains more figures than are significant   ex
3.6247 3 sig fig 3.62   7.5647 4 sig fig
__________   6.2501 2 sig fig
__________   3.250 2 sig fig
__________   7.635 3 sig fig
__________   8.105 3 sig fig __________

• Rounding
• If less than 5, drop it and all figures to the
  right.
• If it is more than 5, increase the number to be
  rounded by one
• If it is 5, and followed by nonzero digit round
  up
• If it is 5, look at the figure to be rounded
• Even , drop 5 and figures that follow
• Odd , round up

7.565
6.3
3.2
7.64
8.10
29
  7. The result of an addition or subtraction
should be reported to the same number of decimal
places as that of the term with the least number
of decimal places.   ex 1611.032
5.6 32.4524
1649.0844?
1649.1
30
8. The answer to a multiplication or division
problem is rounded off to the same number of sig
fig as is possessed by the term having the fewest
significant figures used in the
calculation.   ex 152.06 x 0.24
36.4944?
36
31
Based on the data given which day received the
most rain?
How might this data be better organized?
32
The End
33
HW Answers Sci. Not. Dim. Analysis

• Review of Scientific Notation
• I. 1. 7.42 x 102 3. 6.54000 x 101
• 2. 4.6 x 10-2 4. 5.287000 x
  102
• II. 6. 60 000 9. 0.0005280
• 7. 0.093 10. 100.0
• 8. 6.4 11. 88,000
• III. 12. 8.8 x 103 16. 9 x 102
• 13. 1.9 x 104 17. 1.1 x 108
• 14. 5.7 x 10-3 18. 9.99 x
  10-1
• 15. 3.6 x 10-3 19. 2.5 x 10-4

34
HW Dimensional Analysis Practice Problems

• 1. 4,741 km
• 2. 7.265 L
• 3. 0.93 mi
• 4. 0.918 g
• 5. 2.40 mL
• 6. 8 servings
• 7. 27.8 m/s
• 8. 7.99 g/mL
• 9. 6.25 x 106 kg
• 10 0.0964 mm

35
Significant Figures and Exponential Notation

• 1a) 2 b) 3 c) 3 d) 2
• e) 2 f) 3 g) 2 h) 4
• a) 5.57 x 102 b) 6.4 x 10-2 c) 4.3 x 103
• d) 3.820 x 102 e) 1.18 x 107
  f) 7 x 10-3
• a) 17.9 (3) b) 38.4 (3) c) 66 (2)
• d) 3.99 (3) e) 1.89 (3) f) 0.017 (2)
• g) 7.3 (2) h) 42 (2)
• a) 3.4 x 105 b) 1.67 x 102
• c) 1.7 x 106 d) 1.4 x 10-4
• e) 4.4 x 10-2
• a) 134.6 b) 695.7 c) 1.38 x 1012
• d) 1.7 x 104 e) 1.48 x 10-9