Catchup
Objectives
1. Review returned work (test and
assignment)
2. Fermi
3. Remote Measurement Lab
Engineering Practicum
Baltimore Polytechnic Institute
M. Scott
Ping Pong Anyone?
Solving a problem in 5 minutes (individually)
Look around the room you are sitting in. Answer the following:
How many ping-pong balls could you fit into the room?
Engineering Practicum
Baltimore Polytechnic Institute
M.
W. Scott
Wolfe
Ping Pong Anyone?
Solving a problem in 5 minutes (individually)
Look around the room you are sitting in. Answer the following
questions:
How many ping-pong balls could you fit into the room?
What was your model of a ping-pong ball? What was your
model of the room?
Engineering Practicum
Baltimore Polytechnic Institute
M.
W. Scott
Wolfe
Ping Pong Anyone?
Solving a problem in 5 minutes (individually)
Look around the room you are sitting in. Answer the following
questions:
How many ping-pong balls could you fit into the room?
What was your model of a ping-pong ball? What was your
model of the room?
What other simplifications or assumptions did you make?
Engineering Practicum
Baltimore Polytechnic Institute
M.
W. Scott
Wolfe
Fermi Problems
•Fermi Problems challenge us to ask more questions, not just
provide “an answer.”
•Enrico Fermi (1901-1954) – Italian physicist best known for
contributions to nuclear physics and the development of quantum
theory.
•Fermi used a process of “zeroing in” on problems by saying that
the value in question was certainly larger than one number and
less than some other amount – yields a quantified answer within
identified limits.
•The goal is to get an answer to an order of magnitude by making
reasonable assumption about the situation, not necessarily relying
upon definite knowledge for an “exact” answer.
Engineering Practicum
Baltimore Polytechnic Institute
M. Scott
Enrico Fermi, Physicist
Fermi was one of the most
notable physicists of the
20th century.
He is best known for his
leading contributions in
the Manhattan Project
but his work spanned
every field of physics.
Engineering Practicum
Baltimore Polytechnic Institute
M.
W. Scott
Wolfe
Fermi Electron Theory
While in Pisa, Fermi and his
friends had a well-earned
reputation as pranksters.
One afternoon, while patiently
trapping geckos (used to scare
girls at university), Fermi came
up with the fundamental theory
for electrons in solids.
Fermi’s theory later became the
foundation of the entire
semiconductor industry.
Engineering Practicum
Baltimore Polytechnic Institute
M. Scott
Fermi Problems
Fermi was famous for being able to avoid long, tedious
calculations or difficult experimental measurements
by devising ingenious ways of finding approximate
answers.
He also enjoyed challenging his
friends with “Fermi Problems”
that could be solved by such
“back of the envelope”
estimates.
Laura and Enrico Fermi
Engineering Practicum
Baltimore Polytechnic Institute
M. Scott
Fermi Problems
• Open ended problem solving.
• Thought process is more important than calculating
exact answer.
• Steps in solving Fermi problems
– Determine what factors are important in solving
problem
– Estimate these factors
– Use dimensional reasoning to calculate a solution
Engineering Practicum
Baltimore Polytechnic Institute
M.
W. Scott
Wolfe
Fermi Problems
• What do Fermi Problems have to do with
engineering
– Engineers have to solve open ended problems that
might not have a single right solution
– Engineers have to estimate a solution to a
complicated problem
– Engineers have to think creatively
Engineering Practicum
Baltimore Polytechnic Institute
M.
W. Scott
Wolfe