Transcript Physics Education - University of Colorado Boulder

Physics Education a workshop for physics TA's.
Steven Pollock
+ Qudsia Quraish)
CU Boulder, Aug 2003
www.colorado.edu/physics/EducationIssues/grads
True or False:
Good Teachers are born, not made.
Learning Goals:
• Teaching as a scholarly activity
• Understand "interactive engagement" and
"student preconceptions”
•Applications for your own classes:
• formative assessments
• collaborative learning
• context-rich problems
• supportive classroom environment
• Inspiration : learn more about teaching,
try something research based!
Physics Education Research
In recent years, physics education
research has emerged as a topic of
research within physics
departments. ... The APS
applauds and supports the
acceptance in physics departments
of -The
research
in
physics
education.
American Physical Society
Statement 99.2 Research in Physics Education (May 1999)
Conventional model of teaching:
“transmitting knowledge”
=> lecture/demo
QuickTime™ and a P hoto - JPE G decompressor are needed to see thi s picture.
“I don't think you can teach physics very well
anyway to people in that manner, by giving lectures
on a big scale. I think it's hopeless.”
Richard Feynman: 1918-1988
Constructivist view: Students...
are active in their educational process.
construct understanding based on
prior knowledge.
Assessing Conceptual Mastery
Force Concept Inventory (FCI) *
• 30 multiple-choice question survey
• Covers the most basic concepts in Newtonian mechanics.
• Designed to evaluate effectiveness of instruction
• Based on research & interviews
• Explicit distractors.
*Hestenes, Wells, Swackhamer, Physics Teacher, 20, 1992, p. 141
%gain vs
%pretest
<<g>> = post-pre
100-pre
6000+ students:
Traditional vs. Interactive Engagement
<<g>> = post-pre
100-pre
red = traditional
green = interactive engagement
Fewer than 5% of our physics 1110 students
are likely to become physics majors.
Our students are not all like us...
Assessment of learning
8V
Find the current through the 2 ohm
resistor and the potential difference
betwen points a and b.
1
b
2
a
12 V
(75% vs 40%)
1
E. Mazur (Harvard)
"Context Rich Problem”
You're reading an article in the local paper about
lightning deaths in Colorado, when you run across an
impressive "factoid": the earth's surface has an average
electric potential of a million volts. You're suddenly
struck by a mental image of the earth as a gigantic
spherical capacitor! You start thinking about this and
wonder - could we make use of the resulting stored
electrostatic energy as a significant long term "energy
supply" for our electric needs?
Concept Test (skiier)
A skier on frictionless snow (so common in Colorado) is cruising
gently along the flats, when she spots a symmetrical dip.
She can go down and back up the dip, or ski horizontally across a
bridge. Which path will get her to the far side faster?
PINK: Bridge is faster
BLUE: Dip is faster
GREEN: Same
PURPLE: Not sure
?
CT (eye)
A bundle of parallel rays approaches the eye and some of the rays
enter the eye's pupil, as shown below. No other rays enter the eye.
What does the eye see?
Eye
PINK: A single point of light, surrounded by blackness.
GREEN: A uniformly illuminated wall of light, like a white wall.
BLUE: Many scattered points of light, like stars in the night sky.
YELLOW: None of these.
CT (force)
In the 1600's, Otto Van Güricke, a physicist in
Magdeburg, fitted two hollow bronze hemispheres
together and removed the air from the resulting sphere
with a pump. Two eight-horse teams could not pull the
spheres apart, even though the hemispheres fell apart
when air was re-admitted.
Suppose von Güricke had tied both teams of horses to one
side and bolted the other side to a heavy tree trunk.
In this case the tension in the rope would be...
PINK: twice
BLUE: exactly the same as
YELLOW: half
PURPLE: (not sure)
...what it was before.
(The end...)
National Achievement Level
Results across years – grade 12 science
http://nces.ed.gov/nationsreportcard/science/results/
How are we doing? (TIMSS)
…
http://timss.bc.edu
Another context rich problem
You’re flying into DIA when the pilot says the plane can't land
because of airport delays - you have to circle the airport. She also
tells you the plane will maintain a cruising speed of 400 mph at an
altitude of 15,000 feet wile traveling in a horizontal circle around the
terminal. To pass the time, you decide to figure out how far you are
from the airport. You notice (looking out the window) that to circle,
the pilot banks the plane so the wings are oriented roughly 10
degrees from horizontal. An article in your in-flight magazine
explains that planes fly because air exerts a force, called "lift", on the
wings. The lift is always perpendicular to the wing surface. The
article also gives the weight of a 727 as 100*10^3 pounds, and the
length of each wing as 150 feet. It gives no information on the thrust
from the engines or the drag on the airplane.