https:///astrobaki/index.php?title=Oom_Lecture_01&feed=atom&action=historyOom Lecture 01 - Revision history2022-09-24T16:08:42ZRevision history for this page on the wikiMediaWiki 1.35.1WikiSysop: Created page with '<latex> \documentclass[11pt]{article} \def\inv#1{{1\over #1}} \def\ddt#1{{d #1 \over dt}} \def\ddx#1{{d #1 \over dx}} \def\dtdtt#1{{d^2 #1 \over dt^2}} \def\ppt#1{{\partial #1 \…'2010-02-16T23:34:16Z<p>Created page with '<latex> \documentclass[11pt]{article} \def\inv#1{{1\over #1}} \def\ddt#1{{d #1 \over dt}} \def\ddx#1{{d #1 \over dx}} \def\dtdtt#1{{d^2 #1 \over dt^2}} \def\ppt#1{{\partial #1 \…'</p>
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\usepackage{graphicx}<br />
\usepackage{fullpage}<br />
\usepackage{amsmath}<br />
\begin{document}<br />
Everyday estimation problems:<br />
<br />
\begin{itemize}<br />
\item How many plumbers are there in Berkeley?<br />
<br />
Population of Berkeley: $few\e5$, breakable fixtures per person: few,<br />
fixture breakage rate: 1 per 10 years, so the demand is $few\e4$ fixtures per<br />
year. If a year is 250 work days, and a plumber can fix 3 fixtures per<br />
workday, then it takes 50 plumbers to meet the demand of Berkeley. The yellow<br />
pages has 200 listings.<br />
<br />
\item How much lipstick has Brittany Spears eaten?<br />
<br />
{\bf Substitute} chapstick for lipstick. Then {\bf think in bulk}: Eugene<br />
uses 1 stick every 2 months. Then {\bf take data}: chapstick is 5 grams.<br />
Brittany Spears is 25 and has probably been using lipstick for 15 years.<br />
So at 30 grams per year, for 15 years, this is about 1 lb. of worn lipstick.<br />
How much of this did she eat? Eugene says the efficiency factor is O(1).<br />
So BS has probably eaten 0.5 lbs.<br />
<br />
\item Amount of money in an armored car?<br />
<br />
The {\bf natural length scale} of the problem is that of a human, so we'll<br />
say this car is 6x6x12 ft. A bill is (performing a {\bf measurement})<br />
5x3 inches. What about thickness? Thinking in {\bf bulk}: a 500 page book<br />
is about 2 inches. This comes to $1\e7$ bills in a truck. If these are 20's,<br />
we have $2\e8$ dollars. At 1g per bill, this comes to 10 metric tons, and<br />
that's a little full. We'll say you can only fill a truck to 3, which means<br />
there are 70 million dollars in a full armored car.<br />
<br />
\end{itemize}<br />
<br />
\end{document}<br />
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