Physics 211
(welcome!)
Instructor: Chris Coffin
Wngr 283
coffinc@physics.oregonstate.edu
Classroom Courtesy
Spend your tuition as you wish, but you must let
others hear and see for the entire 50 minutes. So…
Don’t be late. Class starts at the top of the hour.
Silence your phone/tablet/computer
Do NOT start packing up before the lecture ends.
What are you going to do in this course?
1. Practice using your own words to express the
ideas of physics and the methods of science.
2. Practice using your own words to translate
from a real-life situation to a mathematical model.
3. Practice using your own words to reason
through a situation you’ve never encountered
before—but using principles you already know.
Using your own words is a major portion of the credit in
this course. Guessing is not rewarded.
No exam answer (not even a T/F/N question) is accepted as
correct until/unless you explain in your own words/methods
why and how it’s correct.
Why? Because in the real world (any profession, almost
any endeavor), simply being right isn’t enough.
You have to convince others that you’re right.
Evaluate the following statement (T/F/N):
“February has 29 days.”
1. True
2. False
3. Not enough information.
How to Do Well in This Course
(and see also the Syllabus)
Stay caught up! Use the resources offered on the
Course Calendar; budget enough time/energy).
Be prepared! Do the guided study!
Be an active learner. What’s that? For one
thing, it means, “Use your own words.”
Can you finish this common saying?
“You never really understand something until
you can ___________________________ .”
Why MUST you use active learning
to succeed in this course?
Because physics is all about understanding—not
memorizing.
Think about it….
The forest… the trees… the roots…
Biology is staggeringly complex: untold billions of
organisms and relationships—all formed by fewer
than 100 chemical elements.
But what governs the chemistry—and the universe
it sloshes around in? How does it hold together?
Or move? Or expand?
Just a few very powerful principles.
(zoom in….)
And how do we express those principles? How
do we describe the few deep consistencies of the
universe? With mathematics.
Math is the language. Physics is the story. It’s a
story of principles, not facts: unraveling those few
principles requires deductive reasoning (yet a third
“language” or way of thinking). You’re not here to
memorize facts. Your goal is to understand how
the facts arise—even predict them—from the
principles.
Concentrate on the Principles
Your study should never be verbatim “rehearsal”
for the exams. The exam questions/problems will
be ones you’ve never seen before.
So if you understand the principles—and if you can
translate your words into mathematical language —
you’ll be able to handle those questions. You’ll be
at least “conversational” in the language and logic
of the universe. This takes practice.
And you must choose your words well:
Let them enhance, rather than obscure, your meaning.
“To be or not to be…”
“Four-score and seven years ago,…”
“There is no frigate like a book…”
“When in the course of human events,…”
“I pledge allegiance to the flag…”
“Two roads diverged in a yellow wood…”
“Keep things as simple as possible—but no simpler.”
Don’t forget: All language has context
(definitions, assumptions, references, syntax, etc.)
“Bleen viptelmorger fixa quocedj sheka wuzzy g’hadthl.”
(“It will be mostly fair today, with highs in the mid-70’s.”)
So when you use math to describe the universe, equations are useless
unless you know (i) what you’re saying with them (so you must know
how to translate—how to say it in your words!); and (ii) when/how
the equations apply—and when they don’t.
Again, this reminder: The exam questions/problems will
always be new—you won’t have seen them before.
Why? Two reasons:
(1)So that I know you’re understanding the principles, not
memorizing solutions. That’s the “school” reason.
(2) Because new problems are the only kind you’ll ever get
paid to solve. That’s the real-life reason.
And new problems aren’t simple. And they don’t have a
big label stuck to them, saying “Use this tool or that tool!”
You have to diagnose what’s involved—what combination
of tools actually apply. And every situation will have a
different, unknown mix of features. (Welcome to real life.)
And usually, you have to decide what kind of solution is
appropriate—so you know what tools are appropriate—
because real-life problems don’t generally have one
solution or one answer. In fact, your assumptions will
govern how you approach the problem.
How long is the Oregon coast?
Discuss this in small groups until each of you could...
• Clearly state your assumptions
• Succinctly explain why your result is
reasonable