1. Units and Measurement

2. Take your phones out Call the number 303-499-7111
What do you hear?
It is the standard for a SECOND.
At National Institute of Standards and Technology (NIST) in Boulder Colorado, Atomic clocks set the standard for ‘1 second’.

3. Math and Units SI Units – International System MKS Meter m Mass kg
Time s
NIST (was called National Bureau of Standards)
Prefixes

4. Measure the width of your palm

5. SI Unit Prefixes - Part I
Name
Symbol
Factor
tera- T
1012
giga- G
109
mega- M
106
kilo- k
103
hecto- h
102
deka- da
101

6. SI Unit Prefixes- Part II
Name
Symbol
Factor
deci- d
10-1
centi- c
10-2
milli- m
10-3
micro- μ
10-6
nano- n
10-9
pico- p
10-12
femto- f
10-15

7. The Seven Base SI Units
Quantity
Unit
Symbol
Length
meter m
Mass
kilogram kg
Temperature
kelvin K
Time
second s
Amount of Substance
mole
mol
Luminous Intensity
candela cd
Electric Current
ampere a

8. Derived SI Units (examples)
Quantity
unit
Symbol
Volume
cubic meter m3
Density
kilograms per cubic meter
kg/m3
Speed
meter per second
m/s
Newton
kg m/ s2 N
Energy
Joule (kg m2/s2) J
Pressure
Pascal (kg/(ms2) Pa

9. SI Unit Prefixes for Length
Name
Symbol
Analogy
gigameter Gm
109
megameter Mm
106
kilometer km
103
decimeter dm
10-1
centimeter cm
10-2
millimeter mm
10-3
micrometer μm
10-6
nanometer nm
10-9
picometer pm
10-12

10. M x 10n Scientific Notation M is the coefficient 1<M<10
10 is the base
n is the exponent or power of 10

11. Other Examples:
5.45E or
5.45 x 10^6

12. Numbers less than 1 will have a negative exponent
Numbers less than 1 will have a negative exponent. A millionth of a second is: sec 1x E-6 1.0^-6

13. Factor-Label Method of Unit Conversion
Example: Convert 5km to m:
Multiply the original measurement by a conversion factor.
NEW UNIT
85km x 1,000m = ,000m
1km
OLD UNIT

14. Example: Convert 789m to km:
789m x 1km =0.789km= _____??
1000m

15. Convert km/h to m/s
75.00 km x 1000 m x 1 h___ = 20.83m/s h 1 km 3600 s

16. Limits of Measurement
Accuracy and Precision

17. Accuracy - a measure of how close a measurement is to the true value of the quantity being measured.

18. Example: Accuracy
Who is more accurate when measuring a book that has a true length of 17.0cm?
Susan:
17.0cm, 16.0cm, 18.0cm, 15.0cm
Amy:
15.5cm, 15.0cm, 15.2cm, 15.3cm

19. Precision – a measure of how close a series of measurements are to one another. A measure of how exact a measurement is.

20. Example: Precision
Who is more precise when measuring the same 17.0cm book? Susan: 17.0cm, 16.0cm, 18.0cm, 15.0cm Amy: 15.5cm, 15.0cm, 15.2cm, 15.3cm

22. Example: Evaluate whether the following are precise, accurate or both.
Not Precise
Not Accurate
Precise
Accurate
Precise

23. Significant Figures
The significant figures in a measurement include all of the digits that are known, plus one last digit that is estimated.

24. Centimeters and Millimeters

25. Finding the Number of Sig Figs:
When the decimal is present, start counting from the left.
When the decimal is absent, start counting from the right.
Zeroes encountered before a non zero digit do not count.

26. 100
0.001
10302
1.0302x104
How many sig figs?

27. Sig Figs in Addition/Subtraction
Express the result with the same number of decimal places as the number in the operation with the least decimal places. Ex: 2.33 cm cm 5.3 cm (Result is rounded to one decimal place)

28. Sig Figs in Multiplication/Division
Express the answer with the same sig figs as the factor with the least sig figs.
Ex: cm
x cm
6.4 cm2 (Result is rounded to two sig figs)

29. Counting Numbers Counting numbers have infinite sig figs. Ex: 3 apples
WHY?

30. White Board Activity Work in groups of 3
Explain on the given white board
You will present in 15 minutes. C
The two lines AB and AC are 2 sides of a parallelogram. Come of with at least 2 Methods to draw the perpendiculars on a graph paper. B A

31. VECTORs