In order to find the energy stored by the car, let's use the formula below:
![E=Q\cdot V](https://img.qammunity.org/2023/formulas/physics/college/n9sl3bkzbgs3q6437yngobr4op8ulk51sp.png)
Where E is the electrical energy, Q is the charge and V is the potential difference (voltage).
So, for Q = 15.4 C and V = 9.16 * 10^8 V, we have:
![\begin{gathered} E=15.4\cdot9.16\cdot10^8 \\ E=141.064\cdot10^8\text{ J} \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/kyzy9dvjf2g16u5j69tlh1mx0hlo3gvotc.png)
Now, converting this energy into kinetic energy, we have:
![\begin{gathered} E_k=(mv^2)/(2) \\ 141.064\cdot10^8=(1780\cdot v^2)/(2) \\ 141.064\cdot10^8=890v^2^{} \\ v^2=(141.064)/(890)\cdot10^8 \\ v=0.398119\cdot10^4 \\ v=3981.19\text{ m/s} \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/3smax6wg5gfo7q446ca8h138979w5yam8k.png)
Therefore, putting the answer with 3 significant digits, the velocity of the car would be 3980 m/s.