On Mar 14, 8:08*am, Cecil Moore wrote:
Keith Dysart wrote:
You need to read more carefully. I made no statement about
the energy incident upon port 2, only about the energy
flowing into port 2, which, after the 18 W generator is
turned on, is
Pcp2(t) = 32 + 68cos(wt)

If we have two pipes each carrying one gallon of water
per minute in opposite directions, we can agree that
the net flow of water is zero. But you are taking it
one step farther and arguing there is no water flowing
at all which is a ridiculous assertion. I'm going to
ignore this latest obvious diversion.
--
73, Cecil *http://www.w5dxp.com

If there were two transmission lines, then I could see
why you might want two pipes in an analogy.

But since there is only one transmission line, an
analogy with one pipe makes more sense.

So you want to argue that when there is one pipe
with no water flowing, what is really happening is
that one gallon per minute is simultaneously flowing
in each direction. In the same pipe. At the same
time. I don't buy it.

You should think a bit more about
Pcp2(t) = 32 + 68cos(wt)

It is the time rate of energy flow into the port.
It can trivially be computed from the voltage and
current functions at that port.

It sums with the energy flows into the other ports
appropriately to satisfy the principle of conservation
of energy.

All is well.

And there is only one pipe for each port.

...Keith