The torque of a clockwise rotating system is into the paper or away from the
viewer along the axis of the system.

Looking at an inboard drive system from the stern, if the propeller turns
clockwise (torque towards the bow) and the blades are pitched so the thrust
is directed aft is there less strain on the drive system than if the pitch
of the blades were opposite directing the thrust aft for the same sense of
rotation?

Charles Momsen wrote:

The torque of a clockwise rotating system is into the paper or away from the
viewer along the axis of the system.
Interesting (in the pathological sense) mis-definition of torque you are
trying to get us to swallow . . .


Dictionary: torque (1) (tôrk) n.

1. The moment of a force; the measure of a force's tendency to
produce torsion and rotation about an axis, equal to the vector product
of the radius vector from the axis of rotation to the point of
application of the force and the force vector.
2. A turning or twisting force.

http://www.answers.com/topic/torque


Looking at an inboard drive system from the stern, if the propeller turns
clockwise (torque towards the bow) and the blades are pitched so the thrust
is directed aft is there less strain on the drive system than if the pitch
of the blades were opposite directing the thrust aft for the same sense of
rotation?


Gobbledegook. Reverse the blade pitch and keep the sense of rotation
the same and thrust reverses.

Commiserations, you've just failed the Turing test.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.

"Ian Malcolm" wrote in message
...
Charles Momsen wrote:

The torque of a clockwise rotating system is into the paper or away from
the viewer along the axis of the system.
Interesting (in the pathological sense) mis-definition of torque you are
trying to get us to swallow . . .


Dictionary: torque (1) (tôrk) n.

1. The moment of a force; the measure of a force's tendency to produce
torsion and rotation about an axis, equal to the vector product of the
radius vector from the axis of rotation to the point of application of the
force and the force vector.
2. A turning or twisting force.

http://www.answers.com/topic/torque


Looking at an inboard drive system from the stern, if the propeller turns
clockwise (torque towards the bow) and the blades are pitched so the
thrust is directed aft is there less strain on the drive system than if
the pitch of the blades were opposite directing the thrust aft for the
same sense of rotation?


Gobbledegook. Reverse the blade pitch and keep the sense of rotation the
same and thrust reverses.

Commiserations, you've just failed the Turing test.

Nope, you just passed my test. Great job, but your explaination could have
been a bit simpler by pointing out the torque vector is an imaginary
convention (the forces involved in it are orthogonal to the vector which is
a result of cross product operation), whereas thrust is a real force. Well
done Ian!

Charles Momsen wrote:

Nope, you just passed my test. Great job, but your explaination could have
been a bit simpler by pointing out the torque vector is an imaginary
convention (the forces involved in it are orthogonal to the vector which is
a result of cross product operation), whereas thrust is a real force. Well
done Ian!

Tell you what, hold out your arm, I'll clamp a 48" monkey wrench down on
your wrist, then we'll hang a 30 pound weight at the distal end of the
wrench, this will produce an "imaginary" torque of 120ft-lbs on your
wrist. Then you can tell us if it's a real thing or not.....

Cheers
Martin

Charles Momsen wrote:
Nope, you just passed my test. Great job, but your explaination could have
been a bit simpler by pointing out the torque vector is an imaginary
convention (the forces involved in it are orthogonal to the vector which is
a result of cross product operation), whereas thrust is a real force. Well
done Ian!

Marty wrote:
Tell you what, hold out your arm, I'll clamp a 48" monkey wrench down on
your wrist, then we'll hang a 30 pound weight at the distal end of the
wrench, this will produce an "imaginary" torque of 120ft-lbs on your
wrist. *Then you can tell us if it's a real thing or not.....


That would produce TWO torques, one at wrist and one at shoulder.

When evaluating these kinds of things, it is well to remember that a
force which produces no motion does no work... OTOH energy does not
cancel itself out, as "Charles Momsens" first post seems to suggest.

DSK

"Marty" wrote in message
...
Charles Momsen wrote:

Nope, you just passed my test. Great job, but your explaination could
have been a bit simpler by pointing out the torque vector is an imaginary
convention (the forces involved in it are orthogonal to the vector which
is a result of cross product operation), whereas thrust is a real force.
Well done Ian!

Tell you what, hold out your arm, I'll clamp a 48" monkey wrench down on
your wrist, then we'll hang a 30 pound weight at the distal end of the
wrench, this will produce an "imaginary" torque of 120ft-lbs on your
wrist. Then you can tell us if it's a real thing or not.....


The torque vector is an imaginary convention. The forces are not. Just what
I said and what you don't understand.

wrote in message
...


OTOH energy does not
cancel itself out, as "Charles Momsens" first post seems to suggest.

DSK

I'll refer you to the Poynting Vector of the near field of an antenna. The
vector shows at different times an energy flow away from the antenna and
towards the antenna. The net energy flow over time is zero. It depends how
one measures energy, in that example measured over time across a surface it
indeed cancels with each cycle of the electromagnetic wave.

An tangential electric field impinging onto a metal surface is driven to
zero by the reaction of the conductor, the energy is cancelled - driven to
zero since the electric field is zero by the reaction of the conductor.

Magnets stick to each other with opposing polarity - driving the net field
to zero, hence its energy. Same with charge.

Take the electron orbiting the atom. The electron is in a circular orbit,
which by definition is an acceleration. An accelerated charge radiates. So
if the electron is radiating, over time the orbit should collapse since the
energy sustaining its orbit is radiated. Yet the electron does not collapse,
atoms have been around a very long time. That's because the energy radiated
by the electron alters between 2 types of field and the energy that would
have been radiative ends up cancelling itself and is not radiated. This
condition only occurs under particular orbital path lengths (orbits are
quantized for a reason, if the orbit is not following the correct quantized
path then the atom radiates - light, heat, x rays, radio waves, etc and the
atom goes to a new energy state or separates in constituent parts).


Energy has amplitude, phase, location, direction and exists over time, it
certainly can cancel itself out. If it didn't atoms would not exist. Can you
name a natural system that doesn't drive itself to the point of lowest
energy?

In a macroscopic sense, on a large scale bulk measurement mechanical energy
does not tend to cancel itself out. On the atomic or quantum level it can
very well cancel itself out, as well on large scale electromagnetic
phenomena.


In the propeller example what force is exerted in the direction of the
torque vector? None, the forces that create the imaginary convention of
torque vector are at right angles to it. The unit of the torque vector is
not force. The torque vector and thrust lay along the same axis, but thrust
is a force and the torque vector is an imaginary convention. The forces
creating the torque vector is at right angle to the thrust. It's not even a
question - it was jibberish. Ian is correct.

Torque vector is not synonymous with "torque" as it is commonly used or
understood.

Charles Momsen wrote:
"Marty" wrote in message
...
Charles Momsen wrote:
Nope, you just passed my test. Great job, but your explaination could
have been a bit simpler by pointing out the torque vector is an imaginary
convention (the forces involved in it are orthogonal to the vector which
is a result of cross product operation), whereas thrust is a real force.
Well done Ian!
Tell you what, hold out your arm, I'll clamp a 48" monkey wrench down on
your wrist, then we'll hang a 30 pound weight at the distal end of the
wrench, this will produce an "imaginary" torque of 120ft-lbs on your
wrist. Then you can tell us if it's a real thing or not.....


The torque vector is an imaginary convention. The forces are not. Just what
I said and what you don't understand.



So sorry Chuck, I guess was really responding to the first line of your
original question "The torque of a clockwise rotating system is into the
paper or away from the viewer along the axis of the system." Here you
are clearly talking about a real torque, not some mathematical construct.

At any rate, it was not meant to be taken seriously,,, has everyone
lost their sense of humour?

Cheers
Martin

There are instances of energy cancelling itself out in macroscopic
mechanical systems.

Take any system that sustains standing waves, the energy at each node is
zero.