Hi all, Bruce writes
>Eric;
> explain this quote from you, and then we can move on, "Yes, something
>has to cause the force, but the force causes the motion. "
> What caused that force to push the mouth or hands of the nutcracker
>together on the nut? Explain that for me.
Ok. The nutcracker's arms are both touching the nut. There is little
force applied to the nut. Then the brain sends the signal to the muscle to
increase contraction. There is increased tension in the muscles the
fingers push harder on the nutcracker and there is increased stress on the
nut. This all occurs without motion.
Then as muscle create more force the nut reaches a point where it deforms
and then cracks. The nut cracker then moves because there was a force
applied to it by the fingers. The brain rapidly reduces the signal to the
muscles so that there is some nut left to eat and the brain can make it to
the next day without starving.
So, if we just look at the motion we miss the first paragraph. If you just
look at the second paragraph you may still get the nut, but you get a
better picture of what's going on if you look at both paragraphs.
Cheers,
Eric Fuller
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