a$.$ The initial speed of a body is $3\mathrm{.}78$ m$/$s$.$What is its speed after $1\mathrm{.}9$s if it accelerates uniformly at $4\mathrm{.}12$m$/$s$^2?$ Answer in units of m$/$s$.\mathrm{}$

$\mathrm{}$b$.$What is its speed after $1\mathrm{.}9$s if it accelerates uniformly at $-4\mathrm{.}12$m$/$s$^22$a$?$ A car traveling $37$mi$/$h accelerates uniformly for $9\mathrm{.}3$ s$,$ covering $599$ft at this time. What was the acceleration? Round your answer to the nearest $100$th place. $\mathrm{}$

$2$b$.$ What is the final velocity at this time? Answer in units of ft$/$s