An object at rest will stay at rest and an object in motion will stay in motion at a constant speed and in the same direction, unless acted on by an unbalanced force.” the statement above is newton’s first hypothesis of motion because it makes a prediction. theory of motion because it is a widely accepted explanation. law of motion because it is a factual statement based on observations. explanation of motion because it is widely accepted and based on observations.

Crinoids, also known as sea lilies, appear to be sea plants but are not plants at all. crinoids are an echinoderm species which uses anchoring structures called holdfasts to attach themselves to the sea floor. crinoids were most abundant in pennsylvania during the mississippian period, which ranged from 375 to 320 million years ago. fossils of the crinoids shows that during most of this time pennsylvania was that provided favorable conditions for crinoid growth. a) glacial terrain b) a dry and sandy plain c) mostly mountain ranges d) covered by warm, shallow seas