To calculate the energy lost in a collision involving crumple zones, it's essential to determine the car's initial and post-collision kinetic energy using the formula KE = (1/2)mv². After colliding with a wall, the car's speed is assumed to be zero, indicating that all kinetic energy is absorbed by the wall. The mass of the car remains relevant for calculations, as it does not change during the impact. Understanding the energy transformation is crucial, as it reveals that the lost energy is converted into heat and sound. The crumple zone's purpose is to ensure the car stops effectively, confirming that it is indeed possible for all kinetic energy to be absorbed.