A gun that fired charged particles

[Dart82]

Homework Statement

A gun that fires charged particles accelerates a 5-μC charge from rest through a potential difference of 50,000 V. The particle has a mass of 0.025 kg. With what speed does it leave the gun?

Homework Equations

EPE = KE
(1/2)qV = (1/2)mv^2 , solve for v^2

The Attempt at a Solution

EPE = (1/2) x (5^-6 Coulombs) x (50,000 Volts)

KE = (1/2) x ( 0.025kg) x (v^2)

where the problem lies:
When i solve for velocity i get 3.16 m/s, however the answer my teacher gave to this problem was 4.5 m/s. Am i missing something here??

 

[berkeman]

Are you sure that the electrical potential energy is (1/2)qV?

 

[Dart82]

ahhh...nothing like a good 'ole misprint on the formula sheet to trip you up. thanks for the insight!