Question

1. describe the law of conservation of energy. use a pendulum as an example.

Explanation:

The law of conservation of energy states that energy cannot be created or destroyed, only converted from one form to another. In a pendulum, at the highest points of its swing, it has maximum potential energy (due to its height) and minimum kinetic energy (as its speed is zero). As it swings downwards, potential energy is converted into kinetic energy (it speeds up), and at the lowest point, it has maximum kinetic energy and minimum potential energy. As it swings back up, kinetic energy is converted back into potential energy. Throughout the motion, the total mechanical energy (sum of potential and kinetic energy) remains constant, ignoring air - resistance and friction.

Answer:

The law of conservation of energy states that the total amount of energy in an isolated system remains constant over time, with energy being converted between different forms. In a pendulum, energy is converted between potential and kinetic forms as it swings, while the total mechanical energy remains the same (ignoring non - conservative forces like air resistance).