# The Physics Behind Car Safety

## The Physics Behind Car Safety

• Submitted By: ajmal
• Date Submitted: 02/26/2009 3:23 PM
• Category: Science
• Words: 827
• Page: 4
• Views: 1

Ever since the beginning of time physics has existed. There has always been force, friction, momentum, speed and acceleration. Physics can be applied to almost anything in the world today. One really useful application of physics is in the design of cars. More importantly, in the design of car safety. How does physics apply to car safety you may ask? Physics is an important factor of car safety as seen through the use of seatbelts, airbags and brakes. Seatbelts are used to hold a person in a car to prevent the passenger from flying forward or even some cases, out of the car when is suddenly stops. When a car suddenly stops due to a crash with another object the car decelerates very quickly in a small amount of time. This is explained in Newton’s first law, which states “An object in motion continues in motion with the same speed and direction unless it is acted on by an unbalanced force.” The person in the car moves at the same speed as the car when it is in motion. This continues until the car is stopped in a collision with an object. When the car stops due to the unbalanced force, the passenger continues to move at the original speed of the car. This is called inertia. This is where physics plays a major role in the creation of the seatbelt. The seatbelt acts as the unbalanced force on the passenger and stops them from flying forward or out of the car. The seatbelt goes over the shoulders and chest and another part goes across the pelvis. This large area covered will prevent major injuries to the body in case of a crash because the force is being spread out along a large area. Seatbelts are able to apply the stopping force because a mechanism tightens the seatbelt if the car decelerates too quickly so that the passenger will stay in place. Seatbelts took a lot of knowledge of Newton’s First Law to work, but so do Airbags. Airbags are one of the newest features added to cars. They are usually located in the steering wheel and glove compartment of the car. Some...