Assume that in Figures 2.1 and 2.2 the units for the abscissa are L-' (for k,) and A (for x), respectively. If the particles described by the wave packets I these figures are neutrons, compute their mean velocity (in mlsec), the mean inetic energy (in meV), the corresponding temperature (in Kelvin), and the energy pread (also in meV). Estimate the time scale for the spatial spread of this wave acket.