Estimation+or+Fermi+questions

In the course PHS581 we have done a number of estimation exercises. These are laso called Fermi questions named after Enrico Fermi the Italian physicist who was famed at his back of the envelope solutions to various problems. This served Fermi well as he created the first critical nuclear reaction in Chicago.

Some examples of the estimation problems we have done in class

The gravitational force between two cheerleaders separated by 1m.(about 6 E-11 N)

The electric force between two cheerleaders if one transfer 10% of their electrons(36 E26 N)

The weight of the earth(24 E26 N)

The amount of tread lost by a car tire during each revolution(2.5E-10 m)(about the size of an atom or molecule)

The size of a pit(or bit) on a CD(contains 800Mbytes of data) (1E-6 m)