I am teaching myself simple classical mechanics and have a model of a particle moving in a central,conservative force field in 2D. As a function of time, I can plot the radius vector (nice ellipse as expected) or the velocity vector (...). What I want to do is try and plot this as a vector field so I can visualize the velocity and positions changing with time in one plot. ListVectorPlot is supposed to be able to take a list of {xi,yi} points (I think that these would be the x and y components of my radial position vector at time i) and, at each such point, plot an associated vector field point {vxi,vyi}. I have assumed that the vxi and vyi would be the corresponding x and y components of my velocity vector at the same time step. Clearly I have misunderstood the Mathematica inline help for the function as I just get an error message saying that I am not presenting a valid vector field dataset or list of datasets.

I would be most grateful if someone can point out where I am going wrong. In the trivial example attached I attempt to plot the system at t=0 when my position vector is {5,0} and my velocity vector is {0,2}. I had hoped to see a vertical line, 2 units long, plotted 5 units to the right of the origin on the x-axis.