Final answer:
When a rocket firework is lit, it undergoes changes in energy stores, converting chemical potential energy into thermal and light energy. As it goes up, it converts some of the chemical potential energy into kinetic energy and eventually gravitational potential energy. When it falls back to the ground, the gravitational potential energy is converted back into kinetic energy.
Step-by-step explanation:
When a rocket firework is lit, it undergoes changes in its energy stores. Initially, the chemical potential energy stored in the fuel and oxidizer is converted into thermal energy and light energy when the firework is ignited. As the firework goes up in the air, some of the initial chemical potential energy is converted into kinetic energy, which allows the firework to gain height. At the highest point, the firework has mostly converted its initial chemical potential energy into gravitational potential energy. Finally, as the firework falls back to the ground, the gravitational potential energy is converted back into kinetic energy, causing the firework to accelerate and eventually hit the ground.
Learn more about Energy changes and energy stores