Problem $13\mathrm{.}026-$ Blocks resting on spring

A $5\mathrm{.}000-kg$ block rests on top of a $2-kg$ block supported by$,$ but not attached to$,$ a spring of constant $40\frac{N}{m}.$ The upper block is suddenly removed.

Problem $13\mathrm{.}026.$a $-$ Speed achieved by a block resting on a spring

Determine the maximum speed reached by the $2-kg$ block. $($Round the final answer to three decimal places.$)$

The maximum speed reached by the $2-kg$ block is $\frac{m}{s}.$