Lab 1: Fermi Problems and Other Stuff

Fall 2005


Fermi Problems

I'm looking for order of magnitude estimates, not precise answers! You should round off with reckless abandon, and avoid using a calculator if at all possible.
  1. Estimate the speed, in mph, at which human hair grows.
  2. Estimate the average speed, in mph, at which a human grows from age 0 to 18.
  3. The pump that is draining New Orleans is pumping 27,000 gallons of water every minute. How long do you think it will take to drain the city? The area of New Orleans (not counting lakes and canals) is around 450 square kilometers.


A little brain teaser

You have a drawer containing 8 blue socks, 10 green socks, and 12 orange socks. You would like to wear a matching pair of socks. You grab socks one at a time from the draw. What is the maximum number of socks you need to draw before you have a matching pair in your hands?


Triangles

  1. Using a ruler measure p and q on each of the triangles on sheet one.
  2. Then do the same for the triangles on sheet two.
  3. Determine the values of p/q. What does this ratio tell you?
  4. Invent a name for this ratio.
  5. Get sheet three from Sanjeeva or me and do the problems on it.



[Dave] [Physics I] [COA]

Web page maintained by dave@hornacek.coa.edu.