As a roller coaster car travels down a hill, which type of change in energy allows
it to speed up?
a) potential energy changing into heat energy
b) potential energy changing into kinetic energy
c) kinetic energy changing into heat energy
d) kinetic energy changing into potential energy

The following transition occurs at a molecular level for a substance. what transition corresponds to this change in microscopic structure? the carbon dioxide molecules on the left are in a regular, tightly packed pattern. after heating, it becomes much lower density. a. melting b. boiling c. sublimation d. freezing