Welcome
Physics 102
Professor Lee Carkner
Lecture 1
Questions to Consider
Am I in the right place?
Physics 102: Principles of Physics
Do I have the right stuff?
James Walker, “Physics”
Lab manual
Calculator
WebAssign card
available at register at Runestone Bookstore
Things to Know
Professor
Dr. Lee Carkner
Office Hours
MWF 10-11am
Science 208
 Help session:
 TBA
Lab section
See me after class to change
How Does the Class Work?
Read the book material before class
Do the WebAssign homework
Come to class
Do the PAL discussion questions
Lab once a week
Two tests and final
Web Page
http://helios.augustana.edu/~lc/ph102
Outline gives homework and readings
Lectures posted online before class
Syllabus and WebAssign guide also
posted
Grading
Two tests -- 30%
Final -- 25%
Homework -- 15%
PAL -- 10%
Lab -- 20%
WebAssign
Homework will be entered and graded online
At webassign.com
Click on student login
Username is your first and last name together
(e.g. “johnsmith”)
Institution is “augustana”
Password is same as last semester
Augustana ID number if new to class
After login, click on the current assignment and
complete it
WARNING: Can only submit it twice
If you are new to Webassign read tutorial on
class web page
Homework
Homework will generally be from book
Will be posted on webpage
WebAssign will randomize numbers
Available at noon M,W,F
Due at midnight M,W,F
Cannot turn homework in late or make up
Can drop lowest three
Each homework worth same amount (100
points)
15% of grade
PAL
What is PAL?
Physics Active Learning
Each class you will get a PAL worksheet
Contains questions about the material and
feedback opportunities
Worth 10% of your grade
Need to come to class
Can drop (or skip) three PAL’s
“Physics is your PAL!”
Guidelines for Work Handed In
Written answers must be in complete
sentences
Numbers must have units
Answers must reasonable
If not reasonable, explain why
All work must be neat and easily
readable
Today’s PAL
Please answer the first questions:
What is Physics?
What are my goals in taking Physics?
Feedback:
Please list:
Your major
The highest level of math you have taken
(Algebra, geometry, trig, pre-calc, calc)
Comments
Answers
What is Physics?
Phys"ics (?), n. The science of nature, or of
natural objects; that branch of science
which treats of the laws and properties of
matter, and the forces acting upon it;
especially, that department of natural
science which treats of the causes (as
gravitation, heat, light, magnetism,
electricity, etc.) that modify the general
properties of bodies; natural philosophy.
--Webster’s Dictionary 1913
What is Physics?
Physics is a way of figuring out how
things work
More specifically: what are the
underlying rules that govern how things
work?
We will deal mostly with classical
physics:
i.e. How did things work before 1900?
Why Take Physics?
You may need to know how things
work
You can learn how to:
Use reason and logic
Solve problems
Use mathematics
It is useful to understand how we know
how things work
Thermodynamics
What is thermodynamics?
Thermo
Involves temperature
Dynamics
Involves mechanics
Thermodynamics is the study of
thermal and mechanical energy
How do you transform one into the other?
Where Does Thermodynamics
Come From?
Back in the early 1800’s people figured
out that you can transform thermal into
mechanical energy
Can make a device that turns heat into
work
A heat engine
Problem: sometimes the engine would
turn heat into horrible bodily injury
Need to understand what is going on in
the engine
What is this Stuff?
Liquid Nitrogen
The liquid form of the nitrogen gas that
makes up air
Temperature = 77 Kelvin = -320 F
LN will cause frostburn on contact
What is it doing?
Boiling
Changing phase from liquid to gas
Principles of Thermal Physics
Lets think about the first five key
variables in thermodynamics:
Heat
Work
Temperature
Pressure
Volume
The Pringles Launcher:
A Simple Heat Engine
For the Pringle’s launcher:
How does the P,V and T of the material
inside the can change?
Describe the heat flow
How could you measure the work?
LN and Thermodynamics
Using LN demonstrates how things are
affected by temperature changes
The properties of common objects depend
on temperature
The surface of the Earth is at a very
special temperature (~0 Celsius)
Most of the universe is not
Our common sense about how things
works only applies to a little corner of the
universe
Low Temperature Physics
How is heat transformed into energy?
Heat will expand a gas which in turn can
do work
How does temperature effect molecular
bonds
Low T causes bonds to become less flexible