We know that
• The distance is 15 meters.
,• The acceleration is 5 m/s^2.
,• The initial velocity is zero because he started from rest.
To find the final velocity, we use the following formula.
[tex]v^2_f=v^2_0+2ad[/tex]Use the given magnitudes, and solve for vf.
[tex]\begin{gathered} v^2_f=0^2_{}+2\cdot(5\cdot\frac{m}{s^2})\cdot15m \\ v^2_f=150\cdot\frac{m^2}{s^2} \\ v_f=\sqrt[]{150\cdot\frac{m^2}{s^2}} \\ v\approx12.2\cdot\frac{m}{s} \end{gathered}[/tex]