We can solve the problem by using conservation of energy.
In fact, the electric potential energy lost by the charge when moving through the potential difference is equal to the kinetic energy acquired:
![\Delta U=\Delta K =K_f -K_i =K_f](https://img.qammunity.org/2019/formulas/physics/college/feay2ed7lklw53vvyi7y5nfwhorwp3yd3b.png)
where
is the final kinetic energy, and
is the initial kinetic energy, which is zero since the particle starts from rest.
We can rewrite the equation above as:
![q \Delta V=(1)/(2)mv^2](https://img.qammunity.org/2019/formulas/physics/college/94it3ojiki4v9jl5nc6a1ya0s2oq6mn3rq.png)
where
is the charge of the ion
is the potential difference
is the mass of the ion
is the final speed of the ion
Substituting the numbers and rearranging the equation, we can find the potential difference needed:
![\Delta V=(mv^2)/(2q)=((6.7 \cdot 10^(-27)kg)(1.5 \cdot 10^6 m/s)^2)/(2(1.6 \cdot 10^(-19)C))=4.7 \cdot 10^4 V=47 kV](https://img.qammunity.org/2019/formulas/physics/college/vkkbm7p4csm5hv1qb9fmpb5dbsoo3c5ztz.png)