The answer is C. Electrical;mechanical
To me, that sounds like the "Law of Conservation of Energy".
Answer:
Follows are the solution to the given question:
Explanation:
For point a:

For Point b:


For Point C:
For point D:

2m/s because the hockey puck is traveling at a constant speed ( acceleration is 0 ). Unless something acts on the hockey puck it will travel 2 m/s forever.
A mineral is a naturally occurring, inorganic solid with a definite chemical composition and a crystalline structure formed by geological processes.
A rock is an aggregate of one or more minerals. It may also contain organic remains and mineraloids apart from regular mineral formations. Since rocks vary in their mineral and chemical composition, they are classified according to the process of their formation.