Most riders of this amusement ride may not be aware that there is no engine for operation. Then, how does a roller coaster work? Before actually understanding the mechanism, we have to understand two words from the glossary of physics. They are potential energy and kinetic energy.
Potential energy is defined as that energy that is inherent in a physical system in juxtaposition with conservative force acting on it. On the movement of an object from its position against a force, energy is expended and a potential difference is created. Upon allowing the object to return to its original position the energy supplied is recovered.
The best example here is the thing which has elasticity. Due to the elastic potential energy, elastic materials regain their original position. There are different types of potential energies, like gravitational potential energy, elastic potential energy, chemical potential energy, etc.
The additional energy, which an object obtains because of its motion, is called kinetic energy. The common example of use of kinetic energy is the movement of cycle. The rider of a cycle pedals the cycle to a certain speed and after that it moves with less pedaling on its own.
The kinetic energy so obtained by the cycle is used in facing the air-friction and the resistance of the road. If a dynamo is attached to the wheels of the cycle, then electrical energy is produced. The kinetic energy so produced can be used for converting into other forms of energy.
Extending the example of the cyclist, it can be observed that the kinetic energy of the moving cycle on a steep rise will be converted in to a gravitational potential energy once the cycle reaches the top point. On sliding down the slope, the cycle uses the potential energy to come down.
A section of track at the end of the each block is used for stopping the train if necessary to avoid collision among the trains. Sensors fixed on the block detect the movement of the trains and send signals to the computer system operating the mechanism.