Final answer:
Crumple zones and airbags reduce the force of impact during a collision by increasing the collision time.
Step-by-step explanation:
In a collision, the force multiplied by the time is known as the impulse, while the mass multiplied by the velocity change is known as the change in momentum. The impulse experienced by an object is always equal to the change in its momentum. Safety features like crumple zones and airbags in cars reduce the force of impact by providing a cushion during a collision. They increase the collision time, which decreases the force acting on the car and its occupants.