How does a roller coater changes speed?

Answer 1

as the rollar coaster goes up the "hill" as far as it can go , it is considered. Once there it goes down hill and becomes kinetic energy. The roller coaster changes speeds because of the series of hills it goes up and falls down.

At the top of the first lift hill (a), there is maximum potential energy because the train is as high as it gets. As the train starts down the hill, this potential energy is converted into kinetic energy -- the train speeds up. At the bottom of the hill (b), there is maximum kinetic energy and little potential energy. The kinetic energy propels the train up the second hill (c), building up the potential-energy level. As the train enters the loop-the-loop (d), it has a lot of kinetic energy and not much potential energy. The potential-energy level builds as the train speeds to the top of the loop (e), but it is soon converted back to kinetic energy as the train leaves the loop.