43. [tex]v^{2}-v_{0}^{2}=2as <=> 9-36=2.a.50 => a=-0,27 m/s^{2}[/tex]
[tex]t=\frac{v-v_{0}}{a}=\frac{-3}{-0,27}=.....[/tex] => D
24. 54km/h= 15m/s
[tex]t=\frac{v-v_{0}}{a}[/tex] => a=-2,5 m/s^2
[tex]v^{2}-v_{0}^{2}=2as[/tex] => s=45m =>A
16. [tex]v_{tb}=\frac{\Delta s}{\Delta t}=\frac{0,5t.65+0,5t.45}{0,5t+0,5t}=55km/h[/tex] => A