Andes uses the term "height" to refer to the height of an object relative to the problem's stipulated zero level of gravitational potential energy. However it is really only the difference between two heights that is significant when using energy methods.

If an object is displaced between times 1 and 2, the net change in height during that interval will be equal to the vertical component of its net displacement during that interval:

    h2 - h1 = d12_y      where d12_y is the component of displacement d12 along a vertical y axis.

If qd is the orientation of the net displacement taken counterclockwise from the horizontal, then

   h2 - h1  = d12 * sin (qd12)