If you look into this scenario in detail, you will see how the total angular
and linear momentum is conserved separately. The high velocity gas impacts the
large volume of gas and sends the total mass at an average slower velocity in
the direction that the input stream is moving. The total momentum of the
system would be conserved as always.
In the type of system you are describing, the center of mass of the particles
of gas, etc. continues to move at a constant rate relative to external
observers.
Kinetic energy is present in a significant amount within the high velocity gas
according to most observers and that can be converted into other forms of
energy. Heating of the larger gas cloud would likely be seen in this case,
but other conversions are possible as long as the total amount of energy is
conserved.
The conservation of momentum and the conservation of energy both apply
separately. This can lead to some interesting behavior.
If you accept that the center of mass of a system continues at a constant rate
before and after any local closed system interactions, then the conservation of
momentum is directly demonstrated. If conserved it cannot be converted into
anything else such as energy. I find it easier to visualize by taking simple
systems such as two balls that collide to understand how the rules apply.
Choose the best observation frame to simplify the calculations.
Dave
-----Original Message-----
From: a.ashfield <a.ashfi...@verizon.net>
To: vortex-l <vortex-l@eskimo.com>
Sent: Sat, Feb 8, 2014 3:18 pm
Subject: RE: [Vo]:Linear and Angular Momentum
I understand that is the textbook answer but I have wondered if there
are exceptions.
For example, imagine a nozzle discharging gas at high velocity into
a large volume of gas. Why isn't that momentum converted into heat? If
it were, the heat energy could be converted into something else.
