Answer
Newton's first law states that an object in motion will continue moving at the same velocity unless acted on by a force.
A seat belt can bring a passenger to a gradual stop at a safe rate of deceleration.
Work Step by Step
Newton's first law states that an object in motion will continue moving at the same velocity unless acted on by a force.
When a car comes to a sudden stop, a passenger without a seat belt would continue moving forward at the same velocity until an impact with a dashboard, for example, brought the passenger to a sudden stop. This sudden deceleration is obviously very dangerous.
However, a seat belt can bring a passenger to a more gradual stop at a much safer rate of deceleration. This is much safer than a near instantaneous deceleration.
