A student said, Today, giraffes have long necks that allow them to eat leaves high in trees. They got longer necks by stretching up for even higher leaves. After many generations, the giraffe’s neck was really long. Do you think the student’s explanation for how the giraffe’s neck became long is correct? Explain.

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.