B) The potential energy of the rock is transformed into kinetic energy.
Step-by-step explanation:
Our understanding of Physics tells you the potential energy due to the rock's position in the gravitational field is transformed into kinetic energy as the rock gains speed (and loses height).
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<em>Comment on the problem</em>
There are additional effects not accounted for by this simplified answer, including thermal effects, radiation effects, and sound effects. (In this new age, there can also be energetic effects in dimensions we're not accustomed to considering, including emotional or other effects on—or due to—consciousness.)
To answer this specific problem, the measure of ∡DEF
is 64. I am hoping that this answer has satisfied your query and it will
be able to help you in your endeavor, and if you would like, feel free to ask
another question.