Tangential Velocity (maybe)

[titasdasplus]

What additional description do you require?

Actually I want to know why B will start rotating?

 

[Baluncore]

I assume that vector A rotates about the origin, referenced to the x-axis.
Does vector B rotate relative to vector A, or relative to the x-axis ?

Which tangential velocity is required? Is it the rate of point B about the origin in rad/sec, or distance per second about the origin.
Or is it the instantaneous velocity of point B on the x, y plane ?

Actually I want to know why B will start rotating?

Because it is specified as having an angular frequency.
What alternatives are there?

 

[JimWhoKnew]

In that thread, I did show that the expression gave the right answer in a couple of special cases. Maybe you would find that more persuasive?

You were right, and my "suspicion" was wrong. I misinterpreted the requirement in the OP (see the "edit" in post #29).

 

[Old Man Scho]

Around 200 CE, Ptolemy came close to describing planetary motion within the geocentric model. He used the idea of epicycles which is essentially what we have here

Well, in this case we're describing the orbit of the Moon...