Relate the principle of conservation of energy in an analysis of a roller coastr ride from start to finish.?

Question

PLEASE I REALLY NEED HELP!!

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♥ Emily Price™

Answer 1

The design of a roller coaster is complex, in order to give you the mental highs and mellow points that accentuate those highs.

But the principles used in the running of particular circuit 'round the track are really very simple.

The cars are loaded on a raised platform, which means they have a certain amount of potential energy due to the height they're at. Then the train is released and rolls downward, usually to a curve gaining some speed (changing potential energy into kinetic energy). At the lowest point, or very close too, it encounters the highest "hill" on the track. This is the hill that has the only energy input in the whole circuit. A chain drive engages the train and pulls it up the hill greatly raising its potential energy. Again though, this is energy added to the system, not a change in the form of energy already present.

Now, at the top of that highest hill, the train is released from the chain, having been given that great potential energy. It runs down the great hill's other side, changing potential energy into kinetic energy. As that energy rises, so does the train's velocity. Now there are two main factors at work:  the change of kinetic energy into potential on runs up new hills, and the change back to kinetic energy on runs down their other sides, and the steady loss of total energy due to frictional losses. There is a change in energy not usually thought of as the train's velocity changes directions (velocity is a directional value, and so the energy changes as direction changes) but energy is conserved in each velocity change, up and down changes as well as left/right, front/back.

So you see energy conserved as it changes direction, as well as during shifts between types of energy (kinetic vs. potential). And you see energy slowly bled off as frictional and wind resistance (sort of a friction) losses steadily occur. Eventually, as the ride nears its end, the train encounters a braking system that converts the kinetic energy of the train into heat energy. It does this with a vastly higher degree of friction that has been encountered yet. This is another conservation of energy:  kinetic to heat. All the frictional and wind resistance losses have had the same energy conversion. So all the losses encountered were energy changes, not something truly lost to the universe.

In a similar way, the energy input from the chain early in the ride, though a gain to the roller coaster train, was simply a conversion of the chain's mechanical energy into the great rise in the train's potential energy (and some kinetic energy letting it rise to the top of that high hill). Just another conversion of energy, not a gain to the universe.

Finally, a smaller braking system performs similarly to the bigger one to bring the train to a halt on the loading platform. It still has the potential energy that it will convert, after loading, to the kinetic energy required for rolling to the beginning of that chain drive.

By the way, the passengers are part of that system as well. If one were thrown from the train there would be a loss of energy in the system and it would not speed up as fast going down the next hill. The ride would be less exciting... unless, of course, one thought about her own chance to be thrown off as well...