## Classical / Quantum Exercise #2

#### Please answer the following questions:

- What is the relationship between the deBroglie wavelength and d, a
characteristic linear dimension of a system, if quantum mechanics is needed
to describe the situation? If classical mechanics will suffice?
- Do you use quantum or classical mechanics to determine the properties of
an electron in the ground state of the Bohr atom of hydrogen? Give a
numerical argument based on your answer to 1 above.
- Do you use quantum or classical mechanics to determine the properties of a
10 keV electron in the cathode ray tube of a television set? Give a
numerical argument based on your answer to 1 above.
- Do you use quantum or classical mechanics to determine the properties of a
neutron with 10 MeV of kinetic energy inside a nucleus? Assume the
neutron orbits in a circular orbit about the size of a typical nucleus ~10
^{-14
}m. Give a
numerical argument based on your answer to 1 above.

#### Credits

Questions by Larry Cain.