Final answer:
Airbags keep your head and chest from striking the dashboard or windshield in a collision by deploying upon impact, extending the time of impact and lessening the force exerted on passengers to reduce injuries.
Step-by-step explanation:
The component that keeps your head and chest from striking the dashboard or windshield in a collision is the airbag. Airbags are designed to deploy upon impact to minimize serious injuries to passengers. They do this by allowing the net force on the occupants in the car to act over a much longer time when there is a sudden stop.
Thus, while the momentum change is the same, the force that brings the occupant to a stop will be significantly less if it acts over a larger time, demonstrating an inverse relationship between force and time during an impulse.
Cars are also designed with parts that can crumple or collapse during accidents, effectively extending the time of impact and lessening the force exerted on the passengers, which is crucial for reducing injuries.