Seat Belts & Newton's Second Law of Motion

Newton's Three Laws of Motion are all physical laws focusing on the relationships between force, velocity, mass and acceleration. Newton's Second Law can be applied to understand the effectiveness of wearing seat belts to prevent injury and death during collisions.

Significance

Newton's Second Law of Motion is the most powerful and influential of Newton's three laws because of the equation provided and quantitative calculations it encompasses, rather than laws that are just a statement or idea.

Facts

Newton's Second Law focuses on the relationship between mass, acceleration and force of an object. This relationship is expressed by this equation: force = mass x acceleration.

Features

When applying Newton's Second Law of Motion to car accidents and the use of seat belts, the net external force on a passenger's body is the mass of the vehicle multiplied by its acceleration.

Benefits

The proper use of a seat belt reduces the external force of an accident and disperses the initial inertia of the collision across the body.

Warning

Without a seat belt, the passenger's acceleration coupled with the car's deceleration, increases the total acceleration. When this acceleration is being multiplied by a very large mass, even a small change in acceleration results in a large increase in the force being applied to the accident victim.

References

• Newton's Three Laws of Motion
• Seatbelts: Why You Should Use Them