Question

How does Newton’s first law help explain how seat belts work when a vehicle abruptly stops?

A) Seat belts negate the forces acting on a person’s body.
B) Seat belts exert a force equal and opposite to the force the vehicle exerts on a person’s body.
C) Seat belts provide the unbalanced force needed to stop the motion of a person’s body.
D) Seat belts counteract the motion of a vehicle and a body’s momentum to balance the forces acting on the person’s body.

Please select the option that best explains how seat belts work according to Newton’s first law when a vehicle abruptly stops.

Answer 1

Newton's first law, or the law of inertia, explains that seat belts provide the unbalanced force necessary to stop a person's body when a vehicle stops abruptly, thereby reducing the force applied and increasing safety.

Step-by-step explanation:

How does Newton’s first law help explain how seat belts work when a vehicle abruptly stops? The option that best explains this is C) Seat belts provide the unbalanced force needed to stop the motion of a person’s body. According to Newton's first law, also known as the law of inertia, an object at rest will stay at rest, and an object in motion will continue in motion with the same speed and in the same direction unless acted upon by an unbalanced external force. In the case of a vehicle collision, the car abruptly stops, but the passengers inside continue to move forward due to inertia. A seat belt applies an unbalanced force that counters this motion, gradually bringing the passenger to a halt. It effectively increases the time over which the force is applied, as explained by the concept of impulse, thereby reducing the severity of the force on the passenger. This concept also explains why airbags and padded dashboards are important safety features, as by increasing the time of the impact, they reduce the force experienced by the occupants.