What scenario best explains the Law of Conservation of Energy?
A All the energy used to throw a ball is destroyed when it lands
B A car accelerates and begins to gain energy
C When a fish uses all of its energy, it creates more by swimming less
D Light energy is collected by solar panels and transformed into electrical energy
The correct answer and explanation is:
The correct answer is D. Light energy is collected by solar panels and transformed into electrical energy.
The Law of Conservation of Energy states that energy cannot be created or destroyed; it can only be transformed from one form to another. In this scenario, light energy from the sun is captured by solar panels and converted into electrical energy. The energy is not destroyed; it simply changes from one form to another, which perfectly illustrates the principle of conservation.
In the context of solar panels, photons from sunlight strike the surface of the panel and are absorbed by semiconductor materials. This process excites electrons within the material, generating an electric current. The electrical energy produced can then be used to power devices or be stored for later use. This conversion process highlights the core idea of energy transformation, with no energy being lost, only changed from light energy to electrical energy.
To break down the other options:
- A. All the energy used to throw a ball is destroyed when it lands: This is incorrect because energy is not destroyed when the ball lands; it may be converted into other forms, like heat or sound, but it does not vanish.
- B. A car accelerates and begins to gain energy: While the car is gaining kinetic energy, this does not directly explain the conservation of energy. The energy used to accelerate the car comes from fuel, and it follows the conservation law, but the focus here is more on the source of the energy than on the transformation.
- C. When a fish uses all of its energy, it creates more by swimming less: This option misrepresents energy dynamics. Energy cannot be created by swimming less; the fish uses stored energy for movement, and any unused energy remains within the system, but it cannot generate new energy.
Thus, option D best illustrates the Law of Conservation of Energy.