Re: T. Rex mechanics

[Martin Baeker <martin@raptor.ifw.ing.tu-bs.de>]

The recent discussion about the "kings" mechanics bothers me a bit: All
posters were assuming that the T rex was a static thing.

Sure, if you try to turn a large ladder around , which is completely
rigid, you have to get all the torque into the ground through your feet.
However, if you have two ladders, on in front of you and one behind you
(o.k., you would need for arms to move them around, but this is only
theory...) and turn both of them in oppisite directions, the net torque
through your feet is zero. See the following sketch:

------0------      move to          0
                                   / \
                                  /   \
                                 /     \

You can try this experimentally the following way (I did!): Sit on a
well-greased office chair and take some heavy weight into one of your
outstretched arm. Move the arm quickly and, because of the torque you
exert on the chair and conservation of angular momentum, the chair will
rotate in the opposite direction (you might to have to do this quickly, to
overcome friction.) Now, if you take two weights in each of your hands and
move them simultaneously (see picture above) , the chair remains still.
Short essence of long rambling: If you are a T rex and want to turn around
a corner quicly, you may compensate the torque your body creates by moving
the tail simultaneously.

Now, it is for you experts to tell me whether T rex's weight distribution
would allow this, i.e. whether the tail was heavy enough (and tendons and
sinews etc. would allow for enough bending of the tail).


                   Dr. Martin Baeker
                   Institut fuer Werkstoffe
                   Langer Kamp 8
                   38106 Braunschweig
                   Germany
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                   Fax   00-49-531-391-3058
                   e-mail <martin.baeker@tu-bs.de>