Problem 6.71

An electron with kinetic energy $T \approx 4 \mathrm{eV}$ is confined within a region whose linear dimension is $l=1 \mu \mathrm{m}$ . Using the uncertainty principle, evaluate the relative uncertainty of its velocity.

\Delta v / v \sim \hbar / l \sqrt{2 m T}=1 \cdot 10^{-4}

Wave Properties of particles. Schrodinger Equation.