Final answer:
In a collision between two vehicles moving at the same speed, the one with less mass will suffer a greater impact due to experiencing a larger acceleration or deceleration. This impact is dictated by Newton's second law and the principle of momentum conservation in closed systems.
Step-by-step explanation:
When two vehicles moving at the same speed are involved in a collision, the vehicle that weighs less will take the greater impact.
This is because, according to Newton's second law of motion, the impact force experienced by each vehicle is a result of its mass and the change in velocity the vehicle undergoes during the collision. The same force will result in a larger acceleration (or deceleration) for the vehicle with the smaller mass, corresponding with a greater impact experience.
Momentum, a key concept in collisions, is conserved in a closed system according to the law of conservation of momentum. Whether a collision is elastic or inelastic affects the final velocities post-collision, but not the total momentum of the system. Considering a traffic collision example, two cars of different masses colliding at the same speed, or a car and a parked vehicle colliding, illustrates the momentum distribution and the resulting impacts according to the masses involved and the velocities.