An example, a solar sailing toy: http://wry.me/t/gravity/gravity.html http://wry.me/t/gravity/gravity.html Yes, there's a sqrt. (And another for gravity.) No t

An example, a solar sailing toy: http://wry.me/t/gravity/gravity.html http://wry.me/t/gravity/gravity.html Yes, there's a sqrt. (And another for gravity.) No trig needed or wanted.