We know that
• The initial speed is 40 m/s.
,
• The acceleration is 3.5 m/s^2.
,
• The distance covered is 50 m.
Let's use the following formula to find the final speed.
![v^2_f=v^2_0+2ad](https://img.qammunity.org/2023/formulas/physics/college/vvm74dvjhfotizzmyt60b00pmxpaxrnszh.png)
Where V0 = 40 m/s, a = 3.5 m/s^2, and d = 50m.
![\begin{gathered} v^2_f=(40\cdot(m)/(s))^2+2(3.5\cdot(m)/(s^2))(50m) \\ v^2_f=1600\cdot(m^2)/(s^2)+350\cdot(m^2)/(s^2) \\ v^2_f=1950\cdot(m^2)/(s^2) \\ v_f=\sqrt[]{1950\cdot(m^2)/(s^2)} \\ v_f\approx44\cdot(m)/(s) \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/dk0ip838sq985cnkhu1plbyc3o0msduapb.png)
Therefore, the speed after accelerating is 44 m/s.