Scientists think that our four legged mammals might be the distant ancestors of modern-day whales what evidence seems to support their idea?
a.)animals with similar embryo development
b.)dna evidence
c.)migration patterns
d.)a series of closely related fossils

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.