CH353 - Physical Chemistry I
Spring 2013, Unique 52575


Extra Credit Assignment 3


Purpose: This extra credit opportunity will focus on solving a problem that, at first glance, you have no information to solve.  These types of problems are called Fermi problems (named after physicist Enrico Fermi), and must be solved by breaking the problem down into a series of questions, each of which can be approximated based on your general knowledge of the world.  The classic Fermi problem (which Fermi apparently gave to his freshman physics class on the first day of every semester) is "How many piano tuners are there in Chicago?"  No one knows the answer to this off the top of their head, but if you break the question down into a series of simple questions (how many people live in Chicago, how many of these people might have pianos, how long does it take to tune a piano, how often is a piano tuned), then take an informed guess at the answer, not exact but order-of-magnitude, then you can arrive at a logical result fora  seemingly impossible question.  If you have never seen Fermi problems, I suggest you do a bit of Googling to see a few examples.   

Assignment:  Answer the Fermi problem below and write (type) an explanation of your answer.  There is no correct answer to this question; what is important is that you break the question down into a series of logical statements about which you can make an educated guess based on your general knowledge of the world.  It is important that you not use any outside resources for this - the whole point of a Fermi problem is to find an answer with out a textbook or a Google showing you the way.  I of course won't be able to tell if you have used the internet, but you won't get anything out of this if you do.

Problem:  If your car ran on jelly-filled donuts, how many donuts would it take to drive your car from Los Angeles to New York?

Summaries are due at the beginning of class on Monday, 22 April.