Assume the north to be the positive y-direction and east to be the positive x. Resolve the acceleration in both the directions and then apply the equation

for each direction.
So, for north, you have the inital velocity as zero while it is 5m/s for east. After calculating the final velocities in each direction, use pythagoras theorem and find the final velocity.
The direction is given by

is the angle made with the east.
spacetime
www.geocities.com/physics_all/index.html