Starting at t

$=0,$ a horizontal net force F$=(0\mathrm{.}270$N$/$s$)$ti$^+(0\mathrm{.}465$N$/$s$2)$t$2$j$^$

is applied to a box that has an initial momentum p$=(3\mathrm{.}00$kg$$m$/$s$)$i$^+(4\mathrm{.}00$kg$$m$/$s$))$j$^$