Using a motion sensor$,$ Sean finds that the acceleration of a $2-$kg rock that has been dropped from the roof of a building is $5\mathrm{.}5$ m$/$s$2.$ He concludes that the magnitude of force of air resistance acting on the rock is approximately

Group of answer choices

$11\mathrm{.}0$ N

$9\mathrm{.}81$ N

$6\mathrm{.}62$ N

None of these is correct.

$19\mathrm{.}6$ N

$$