The given question asks us to identify the principle that explains why the sum of kinetic and potential energies of a roller coaster remains constant, assuming no friction or air resistance is present.
The correct answer is the Law of Conservation of Energy. Below is a step-by-step explanation of why this is the correct choice and why other options can be ruled out.
- Understanding the concept:
- Potential energy is the energy possessed by a body due to its position or height. At the top of a track, a roller coaster has maximum potential energy.
- Kinetic energy is the energy possessed by a body by virtue of its motion. As the roller coaster descends, it gains speed and increases its kinetic energy.
- Law of Conservation of Energy:
- This law states that the total energy of an isolated system remains constant. Energy cannot be created or destroyed but can change from one form to another.
- In the context of the roller coaster, as it moves along the track, potential energy is converted into kinetic energy and vice versa, keeping the total mechanical energy constant.
- Evaluating the options:
- Law of inertia: This law explains the motion of objects when no external forces act. It states that an object will remain at rest or in uniform motion unless acted upon by a force. It does not concern the conservation of energy.
- Principle of superposition: This principle applies to waves and states that when two or more waves overlap, the resultant wave is the sum of the individual waves. This principle is not relevant to energy conservation.
- Principle of inertia: Similar to the law of inertia, this principle deals with the persistence of motion without external force. It does not deal with energy conservation.
Therefore, the Law of Conservation of Energy is the principle that ensures the sum of kinetic and potential energies remains constant for the roller coaster in the absence of external forces like friction and air resistance.
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