Solution: Radius of curvature

F=1i`+2j`+3k`
V=-2i`+3j`-k`

Now, the component of force perpendicular to the velocity is (m*|V|^2)/r.

This component is |F|*Sin(Q)=2*14/r
or sqrt(14)*Sin(Q)=(2*14)/r

or r=(2*sqrt(14))/Sin(Q)

Q is the angle b/w the 2 vectors F and V.