A rifle fires a $2\mathrm{.}79{10}^{-2}-$kg pellet straight upward, because the pellet rests on a compressed spring that is released when the trigger is pulled. The spring has a negligible mass and is compressed by $6\mathrm{.}75{10}^{-2}m$ from its unstrained length. The pellet rises to a maximum height of $5\mathrm{.}29$ m above its position on the compressed spring. Ignoring air resistance, determine the spring constant.