re: #151 zombie

You seem to be making the problem more complex.

Unfortunately, the inability to embed graphics in comments, plus the difficulty of embedding mathematical formula (though Unicode does give limited capability) makes describing these physics problems quite difficult.

Not that it can’t be done in English, but it becomes very difficult.

Mechanical movement does not preclude other types of forces. E.g., one can use electrostatics (say, the repulsion of electrons) to cause movement of masses.