Final answer:
A vehicle's crumple zones and airbags help reduce damage in a collision by increasing the time of impact, which decreases the force on the occupants, according to the principle of impulse.
Step-by-step explanation:
A vehicle's safety features, such as crumple zones and airbags, help reduce damage that comes from hitting an object of impact. Specifically, these features work by extending the time over which a collision occurs, which in turn reduces the force transmitted to the occupants of the vehicle. Answering the student's question, the correct choice is:
a. It reduces injury to the passengers by increasing the time of impact.
When a car equipped with areas designed to crumple is involved in a collision, the deformation of these parts absorbs energy and increases the duration of the impact. This longer duration allows the occupants' momentum to change over a greater period of time, resulting in lower forces acting on them, which can reduce the likelihood of injuries or fatalities.
This principle is based on the concept of impulse, which is the product of the net force and the time over which the force acts. Both crumple zones and airbags are designed to maximize this time, thus minimizing the forces on passengers and improving safety.