$$ \begin{aligned} v_0 &= 146\ut{km/h} \\ &= 146\ut{km/h}\cdot\frac{1000\ut{m}}{1\ut{km}}\cdot\frac{1\ut{h}}{3600\ut{s}} \\ &= \frac{365}{9}\ut{m/s} \end{aligned}$$ $$ \begin{aligned}\\ v &= 90\ut{km/h} \\ &= 90\ut{km/h}\cdot\frac{1000\ut{m}}{1\ut{km}}\cdot\frac{1\ut{h}}{3600\ut{s}} \\ &= 25\ut{m/s} \end{aligned}$$ $$ \begin{cases} a &= -5.2\ut{m/s^2} \\ v_0 &= \frac{365}{9}\ut{m/s} \\ v &= 25\u..