Nav wrote:

Yes, as I said, no answer from you but one from me.

Yes, as you said... an answer from you... a wrong answer, with no
attempt to explain how you reached it, no mention of any of the other
forces on the system, and total backpedalling once I showed how to set
up the porblem and hinted at resolving all the forces which you could
not identify.

A fine example, Navvie.

DSK