Tree roots cracking rock on the ground is?
a)erosion
b)weathering
c)deposition

some think that theories become laws, but theories and laws have separate and distinct roles in the scientific method. a law is a description of an observed phenomenon in the natural world that hold true every time it is tested. it doesn't explain why something is true; it just states that it is true.

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.