The vpython command norm returns the unit vector of a vector. remember that a unit vector has a length of one and points in the direction of the original vector. for exampe, if l = vector(0,3,0) then norm(l) = < 0,1,0> and, if l = vector(0,3,0) then norm(-l) = < 0,-1,0> additionally, if l = vector(0,3,0) then norm(5l) = < 0,1,0> and, for example, if m = vector(1,1,0) then norm(m) = < 0.707,0.707,0> . another example, if n = vector(2,3,0) then norm(m) = < 0.5547,0.83205,0> an for another example, if p = vector(1,2,3) then norm(p) = < 0.267261,0.534522,0.801784> if q = vector(3,4,0) then norm(q) =