Final answer:
It is true that seat-belts help keep a driver behind the steering wheel and in control during a crash by extending the collision time, which reduces the force exerted on the driver. The longer the collision time, the less force is exerted, due to the principle of impulse.
Step-by-step explanation:
Seat-belts are critical safety features in vehicles that keep a driver behind the steering wheel and in control during a crash. This is indeed true. When a car crashes, the inertia of the driver wants to keep them moving at the same velocity at which the car was traveling before it stopped. The seatbelt restrains them, extending the collision time which, in turn, reduces the force exerted on the driver's body.
This concept is rooted in the physics principle known as impulse, which indicates that force times the time over which it acts (collision time) is equal to the change in momentum. The longer the time over which the force acts, the smaller the force can be to achieve the same change in momentum. Cars with features that crumple during a collision increase the time of impact, which offers more protection to passengers by dispersing the force over a longer period and, as a result, lessening the severity of the force involved.