A $70-kg$ astronaut is space$-$walking outside the space capsule and is stationary when the tether line breaks. As a means of returning to the capsule he throws his $2\mathrm{.}0-kg$ space hammer at a speed of $14\frac{m}{s}$ away from the capsule. At what speed does the astronaut move toward the capsule?

$5\mathrm{.}0$ m$/$s

$0\frac{m}{s}$

$0\mathrm{.}40\frac{m}{s}$

$3\mathrm{.}5\frac{m}{s}$

$1\mathrm{.}5\frac{m}{s}$