A $4\mathrm{.}00$ g bullet has a muzzle velocity of $240$ m$/$s when fired by a rifle with a weight of $20\mathrm{.}0$ N$.$

$($a$)$

Determine the recoil speed $($in m$/$s$)$ of the rifle.

m$/$s

$($b$)$

If a marksman with a weight of $700$ N holds the rifle firmly against his shoulder, determine the recoil speed $($in m$/$s$)$ of the shooter and rifle.

m$/$s