Final answer:
The devices designed to reduce whiplash injuries on the back of front seats are known as headrests. They work in conjunction with seat belts and airbags to protect passengers during a collision by minimizing head and neck movement.
Step-by-step explanation:
The padded devices on the back of front seats designed to help reduce whiplash injuries in a collision are called headrests. They support your head during a rear-end collision and minimize the movement of the head and neck, reducing the risk of a whiplash injury. This safety feature complements other systems like seat belts and airbags, which provide protection during different types of collisions. Airbags, for example, work by deploying upon impact to minimize serious injuries by extending the amount of time over which the force acts on an occupant, thereby reducing the net force. Crumple zones are another safety feature designed to absorb the energy of a collision and increase the time of impact, reducing the force on passengers.