Final answer:
A book on a high shelf has the most potential energy because potential energy is greater at increased heights. A moving car has kinetic energy, a stationary bike has neither significant kinetic nor potential energy, and a falling leaf is converting its potential energy into kinetic energy.
Step-by-step explanation:
The question is about identifying which object has the most potential energy. Potential energy is the energy that an object has due to its position relative to a reference point, often due to gravity. A book on a high shelf will have more potential energy because potential energy increases with height, and the book is elevated compared to the other objects listed. For example, when you drop an astronomy textbook from a significant height, it will release more energy upon hitting the ground than it would from a lower height, indicating it had more potential energy initially. A moving car has kinetic energy because it is in motion, a stationary bicycle has neither kinetic nor potential energy, and a falling leaf is in the process of converting its potential energy into kinetic energy as it falls.
To further elaborate, if two people observed a leaf falling, one from a ladder and the other from the ground, they would find that the kinetic energy of the leaf and the change in gravitational potential energy are the same for both observers. This is because these energies depend on the height from which the leaf falls, not on the observer's position. However, the final gravitational potential energy when the leaf hits the ground is the same for both because it is at ground level where potential energy is zero relative to the height from which it fell.