8/24/2011
What do
these things
have in
common?
Catastrophes due to Unit Conversion Errors
(1999) NASA lost $125 million Mars Climate
Orbiter due to Lockheed Martin giving thruster
data in English units and NASA expecting metric
units.
(1983) Air Canada Flight 143 ran out of fuel
halfway into flight to Edmonton. Due to fuel
units change and loading wrong amount.
(2004) Tokyo Disneyland’s Space Mountain, axle
broke off roller coaster mid-ride due to bolts
machined to specification in English units
instead of metric units.
Announcements
Correction:
The final exam is December 13th from 10:30 am – 1:00 pm.
Now correctly shown on course web page, posted lecture notes, etc.
Clarification:
Everyone must be registered for one “section” – which includes both
recitations and labs (some weeks are recitations and some weeks
are labs). You meet at the same time and place very week.
Enrolled Waitlisted
30
30
30
30
30
28
17
28
30
30
30
30
29
30
29
30
317
Update:
We have increased the enrollment for every “section” by +2 and
thus there are enough total spots for the course for everyone to get
in. However, if you are still on the waitlist for a specific “section”,
you may need to switch to a section with openings.
Go out of this main lecture hall (G1B30), and across the hall are a set of stairs down
to the G2B level. You will see this set of doors (to the Physics Help Room).
Keep going through to G2B83 for your weekly Section.
0
3
0
1
1
0
0
2
0
1
2
1
0
1
0
0
Space Available
To be
increased to
30 students
maximum.
Also, room
number
posted
incorrectly.
Announcements (part 2)
As Requested:
We have added a couple of copies of the textbook on reserve in the
library for the semester (Gemmil library).
Clarification:
The CAPA folders (check for PHYS2010) are downstairs. Each week
that will have a printout of your
assignment and PIN number.
You can always use the PIN getter
on the CAPA page too.
If you are registered very recently
and do not see your printout,
use the CAPA page
“late enrollment” link.
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8/24/2011
Announcements (part 3)
Reminder: Attend your “Section” this week.
Reminder: Math Review Available on Monday 2-3 pm and 3-4 pm
in the same location as your “Section”. Recommended if your
Math Diagnostic score < 5.
Reminder: CAPA Homework #1 due on Friday at 10 pm
Reminder: Textbook Reading – Chapters 1 and 2
Reminder regarding Office Hours
(Nagle/Kinney) Wednesday 1:45-3:45 pm (Help Room)
(Kinney) Thursday 4-5 pm (Help Room)
(Nagle) Monday 2-3 pm (Gamow Tower F221)
(Uzdensky) Tuesday 11 am – noon (Help Room)
Also all Teaching Assistants have Help Room Hours
First session this evening!
Dr. Ariel Paul does a weekly review session at:
Wednesdays at 8:00 pm in Duane G125
Note that sessions start the first week of classes and continue through
the semester. These sessions are not an official part of the course and
are not required. They usually begin with a review of major concepts
covered for the week with an aim at helping common confusions, and
then the discourse is guided by student questions. Feel free to contact
Dr. Ariel Paul for more information ([email protected]).
Your iClicker
Setup your iClicker
Power Indicator (lighted when on)
Low Battery Indicator (<10 h left)
Replace 3 AAA batteries before next class
Vote Status
Green on for 0.5 sec indicates vote received
Flashing Red – not received
Everyday: Swap clicker code to BA:
• Hold down On/Off Switch 4 seconds
• Flashing blue light: hit BA
• DO NOT TURN OFF CLICKER IN CLASS
On-Off Button (keep on during class)
Clicker Question
Room Frequency BA
How would you describe your career ambition?
A)
B)
C)
D)
E)
F)
Pre-Med.
Other medical professional.
Architecture Environmental Design, etc.
Biological scientist, generally speaking
Other
Future Arch-Nemesis of Superman
(repeat above as needed – some clickers may turn off
automatically after some time.)
Clicker Question
Room Frequency BA
Which of the following are SI
“base units”?
A) mm, mg, s
B) cm, g, s
C) mm, kg, s
Meters
D) m, kg, s
Kilograms
Seconds
E) km, g, h
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8/24/2011
For comparison,
British System
Feet (ft)
Pounds (lb)
(actually a unit
of force)
Minutes, Hours,
Years, etc.
Room Frequency BA
Clicker Question
Why can’t we all just switch to metric and be done?
Make an order-of-magnitude estimate for how much $$$ are
currently invested in drill bit sets in
United States households?
A)
B)
C)
D)
E)
$10
$1,000,000
$10,000,000
$1,000,000,000
$1,000,000,000,000
How many US people?
How many US households?
How many have a drill set?
How much does a drill set cost?
100 million x $10 =
(1 x 108) x (1 x 101)
= 109 = 1 billion
Mixed and Derived Units
Velocity, speed
v
m/s
Acceleration
a
m/s2
Momentum
p=mv
kg m/s
Force
F=ma
kg m/s2 = N (Newton)
Energy
E=1/2mv2
kg m2/s2 = N m = J (Joule)
Power
P=E/t
kg m2/s3 = N m/s
= J/s = W (Watt)
Converting Units
I am a little over 6.0 feet tall. In Continental Europe
where they use the metric system, they would say?
Front cover of the textbook says 1 meter = 3.281 feet.
 1 meter 
6.0 feet  
  1.8287 meters
 3.281 feet 
What is the right number of significant figures?
A) 1.8 meters
6.0 has 2 significant figures,
and so 1.8 meters should have
B) 1 meter
the same.
C) 2 meter
D) 1.82 meters
E) 1.838 meters
What if we did not have the textbook available?
What an odd sign.
Most of us know that 12 inches = 1 foot
Most of us know that 1 inch = 2.54 cm (centimeters)
MPH = Miles per Hour
 12in   2.54cm   1m 
  
6.0 feet  
 

 1 ft   1in   100cm 
 12  2.54 
6.0  
 meters  1.82 meters
 100 
Convert to meters/second
Textbook has 1 mile = 1.609 kilometers (km)
We know that 1000 meters = 1 kilometer
We know that 1 hour = 60 x 60 seconds = 3600 seconds
669,136,766
miles  1.609km   1000m   1hr 


 

hour  mile   1km   3600s 
Suddenly I feel shorter!
299,066,960
meters
meters
 3 108
second
second
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8/24/2011
Remember the Metric Prefixes
1,000,000,000 = Giga
1,000,000 = Mega
1000 = kilo
0.01 = 1/100 = centi
0.001 = 1/1000 = milli
0.000000001 =
1/1,000,000,000 = nano
Not really nano,
but just smaller
Remember the Algebra of Exponents
a m  a n  a m n
100,000  105  1032  102103
1
 a m
1
1
m
a
 3  103  0.001
1000 10
m
a
 a m  n 100 102
n
 3  1023  101  0.1
a
1000 10
m n
mn
a
a
2
103  1023  106  1,000,000
 
 
Clicker Question
Room Frequency BA
What’s a Yotta Yotta Yotta?
A)
B)
C)
D)
E)
An annoying phrase from Seinfeld.
1024
10-24
1036
1072
Yotta Yotta Yotta  102410241024  10242424  1072
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8/24/2011
Clicker Question
Room Frequency BA
We found before that there are about 0.305 m/ft.
1 m3 is how many cubic feet (ft3) ?
A)
B)
C)
D)
E)
0.03 ft3
0.3 ft3
3 ft3
11 ft3
35 ft3
See next lecture for answer.
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