The force, F, on a charged particle moving with a velocity, v, in a region with magnetic field, B, is given by

    F = q*v x B

In component form:

    F_x = q*(v_y*B_z - v_z*B_y)

    F_y= q*(v_z*B_x - v_x*B_z)

    F_z = q*(v_x*B_y - v_y*B_x)

The magnitude of the force, F, is given by

    F = abs(q)*v*B*sin(angle between v and B )

and the direction of F is obtained by:

    1.  F is perpendicular to the plane determined by v and B.
    2.  The direction of F perpendicular to the plane is determined by using the right-hand rule which states that F is in the direction that a right-handed screw would move, if it was turned in the direction from v to B through the smaller of the two angles between these two vectors.  See the diagram below.



IMPORTANT ANDES NOTES:

    1.  The Andes workbench always considers the plane of the screen to be the x-y plane.
    2.  To draw a vector in the z-direction one must use the tool on the left hand side of the screen that has a circle with a dot in the center to specify a vector in the positive z-direction (out of the screen) and a circle with a cross in it to specify a vector in the negative z-direction (into the screen).  There is also a spot in the dialog box for vectors that allows these same designations.
    3.  To draw a zero length vector choose the vector tool desired from the vector tools bar and left click in the drawing area.