A firework is shot into the sky. As it is moving up… How the potential and kinetic energies of the firework are changing? What is happening to the total mechanical energy of the firework?

Question

law of conservation of energy

Answer 1

If we ignore air friction and assume it is shot straight up, the total mechanical energy does not change as it rises. The initial kinetic energy it was fired at is related to its speed, which slows as it rises. The kinetic energy lost is converted into greater and greater potential energy as it gets higher above the ground. At its highest point for an instant, it is motionless with no kinetic energy left, but the same amount of total energy in the form of potential energy.