I have a very bright 8th grade
student who asked me something I can't
If one were to put some sort of
mechanism underneath a big rock that converted
the pressure of the rock against the earth into
electricity, then how is that not some sort of
perpetual energy source? The gravitational
potential energy is not changing if the rock is
not moving; yet the pressure it exerts must be a
kind of energy that can be theoretically
converted into electricity, no? The gravitational
energy does not "wear out" in this situation...
so isn't that a perpetual energy source?
I'm just not sure how to answer his question.
He and I both think we understand the basic
concepts of gravitational potential energy and
kinetic energy. Any guidance you can give us on
answering his question would be most appreciated.