The car's velocity at time [tex]t[/tex] is given by
[tex]v=v_0+at[/tex]
where [tex]v_0[/tex] is its initial velocity and [tex]a[/tex] is its acceleration. After 5.00 seconds, we have
[tex]v=4.30\,\dfrac{\mathrm m}{\mathrm s}+\left(3.00\,\dfrac{\mathrm m}{\mathrm s^2}\right)(5.00\,\mathrm s)[/tex]
[tex]\implies v=19.3\,\dfrac{\mathrm m}{\mathrm s}[/tex]
and thus a final speed of 19.3 m/s as well.
