A $0\mathrm{.}450-$kg baseball, thrown with a speed of $35\mathrm{.}0$ m$/$s$,$ is hit straight back at the pitcher with a speed of $45\mathrm{.}0$ m$/$s$.$

$($a$)$ What is the magnitude of the impulse delivered by the bat to the baseball?

$($b$)$ Find the magnitude of the average force exerted by the bat on the ball if the two are in contact for $2\mathrm{.}5\mathrm{.}00$ x $10^-19$ s$.$

Group of answer choices

$4\mathrm{.}50$ kg$/$s; $1\mathrm{.}13$ x $10^-20$ N$/$s

$4\mathrm{.}50$ kg$/$s; $1\mathrm{.}13$ x $10^-20$ N

$4\mathrm{.}50$ kg$.$m$/$s; $1\mathrm{.}13$ x $10^-20$ N

$4\mathrm{.}50$ kg$.$m$/$s; $1\mathrm{.}13$ x $10^-20$ N$.$s