The first law of motion is the most fundamental law governing car crashes. It states that an object in motion will maintain its speed and direction unless acted upon by an external force. Likewise, an object at rest will remain at rest unless another force disrupts it.
Your car will remain in motion unless another vehicle hits it. If the force the other vehicle introduces is great enough to affect the inertia of your car, it may even cause both vehicles to come to a complete stop. Even when a car crash occurs while your car is at rest, it is only because of inertia. Your car was simply resisting the outside force of the object, and that resistance caused the crash.
What is inertia?
The first law of motion is also the law of inertia. Inertia is an object’s passive property to continue in its existing state. It activates when there is an unbalanced force to oppose. The more inertia an object has, the more it can resist an outside force. According to the law, every object has an inherent property to resist the change in its state of rest or motion. Even people have varying quantities of inertia, which is why car crash injuries are never the same.
How does inertia affect car crash injuries?
As a car is in motion, all the objects and people inside the car are moving at the same speed and in the same direction as the car. When a car crashes into something, the car is the first object to absorb the force. The objects inside the vehicle continue moving until they also collide with an object.
The driver and passengers may hit the dashboard, the seat belt, the window or even the car seat in front of them. They sustain injuries proportionate to the net force of the object that their body tried to resist. It explains why people in the same vehicle sustain different injuries. If you are wearing a seat belt, the seat belt is the outside force that stops your body from propelling out of the car.
By understanding the basic physics of a car accident, you will realize what caused it in the first place.