The motion of the particle in this system is helicoidal, with the axial motion uniform (constant) but the radial and angular components varying in a spiral according to the equation of motion derived above. The initial conditions on r, dr / dt, θ, dθ / dt, will determine if the trajectory of the particle has a constant r or varying r. If initially r is nonzero but dr / dt = 0, while θ and dθ / dt are arbitrary, then the initial velocity of the particle has no radial component, r is constant, so the motion will be in a perfect helix. If r is constant, the angular velocity is also constant according to the conserved p θ.