Seat Belts

Seat Belts and Newtons Laws

Seat belts are vital in relation to Newton’s first law of an object in motion continues in motion with the same speed in the same direction unless acted upon by an unbalance force. An example with the law of inertia would be if a vehicle were to collide with a wall, the unbalanced force acted upon the car once contact was made with the wall would abruptly decelerate the vehicle to rest. If a seat belt were worn the passengers in the car would also decelerate to a rest as a result of the passengers sharing the same state of motion as the car when tightly strapped to the vehicle.

Seat Belts

Seat belts are designed to lock in place when an abrupt force is exerted against it. As a result, the occupants are restrained inside the car, which prevents them from maintaining motion with the inertia of the car when the vehicle is forced to change direction or is brought to an abrupt stop. If a vehicle were to stop abruptly, the occupants speed would remain the same and without a seatbelt there is a possibility that the person would slam into the steering wheel or go through the windshield at the same speed the car was travelling at.

Seat belts are composed of two sections. The first part rests over the occupants pelvis with the second part resting over the shoulder and across the chest. If a car were to brake suddenly, the seatbelt applies the stopping force across a large amount of the passengers body, therefore the damage is reduced. When the seat belt is worn correctly, most of the stopping force is applied to the rib cage and the pelvis. Also the seatbelt is composed of webbing, which is much more flexible material than the windshield or dashboard and as a result allows room to stretch meaning the stop isn’t as abrupt.