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.
![v^2_f=v^2_0+2ad](https://img.qammunity.org/2023/formulas/physics/college/vvm74dvjhfotizzmyt60b00pmxpaxrnszh.png)
Use the given magnitudes, and solve for vf.
![\begin{gathered} v^2_f=0^2_{}+2\cdot(5\cdot(m)/(s^2))\cdot15m \\ v^2_f=150\cdot(m^2)/(s^2) \\ v_f=\sqrt[]{150\cdot(m^2)/(s^2)} \\ v\approx12.2\cdot(m)/(s) \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/khkoy6g979yg8v6po6adqmkaeo99ffuhbm.png)
Therefore, the final velocity is 12.2 meters per second.