Question

a ball is dropped in a closed system (no air resistance). what happens to its energy as it falls?
kinetic energy turns into chemical energy.
potential energy changes into kinetic energy, and no energy is lost.
thermal energy increases while total energy decreases.
potential energy disappears before impact.

Explanation:

In a closed - system with no air resistance, the law of conservation of energy applies. The ball initially has gravitational potential energy due to its height. As it falls, its height decreases and its speed increases. According to the energy - conservation principle, potential energy is converted into kinetic energy, and the total mechanical energy (sum of potential and kinetic energy) remains constant.

Answer:

Potential energy changes into kinetic energy, and no energy is lost.