An ion of mass M M\,M and charge Q Q\,Q is accelerated from rest through a potential difference VVV. Which of the following is the correct expression for the final speed v v\,v of the ion?
QV2M\frac{QV}{2M}2MQV
2QVM\frac{2QV}{M}M2QV
QV2M\sqrt{\frac{QV}{2M}}2MQV
2QVM\sqrt{\frac{2QV}{M}}M2QV
