Final answer:
When air resistance is ignored, all cars dropped from the same height would reach the ground at the same speed, as dictated by the conservation of energy and free-fall principles. The potential energy from their original height is converted entirely to kinetic energy, resulting in their speeds being identical regardless of their masses.
Step-by-step explanation:
If all cars were dropped from the same height, under the condition of neglecting air resistance, they will have the same speed upon reaching the ground. This concept is derived from physics, specifically the principle of conservation of energy and the laws of free fall. When a car is dropped, its potential energy is converted to kinetic energy, meaning that its speed just before impact is determined by the original height from which it was dropped, not its mass.
This is assuming that all cars have the same initial speed, which is zero if they are simply dropped. The potential and kinetic energy of the car would both be zero after the car hits the ground.
Furthermore, if we discuss forces and accelerations during the fall, the force of gravity acts equally on all objects in free fall, so assuming negligible air drag and equal masses, all vehicles would accelerate at the same rate due to gravity and thus have the same speed upon collision or impact with the ground.
However, if the masses were not identical, the force experienced by each car would be different due to F=ma (Force equals mass times acceleration), although the acceleration due to gravity would remain the same.