When operating a vehicle, physics is involved in numerous ways. For instance when a car is parked and at rest it represents having an initial velocity of zero meters per second. Also, you have the forces of gravity and normal forces acting upon the car to keep it from moving on earth's surface. Since the vehicle is at rest, it also contains potential energy because its energy is stored and currently not at use. As soon as the car starts moving, you now have kinetic energy which represents the energy of motion and movement. The car is also accelerating and gaining speed, initially increasing its velocity as well. The first law of motion therefore affects us because while we are in a car, no matter how fast the car is going, we are also going that fast and we continue to go that fast until acted upon by an outside force. Therefore if while driving you crash your car, your body will resist the change in motion and unless something else stops it first, your body will crash as well. The invention of seat belts helps protect people from this danger/future accidents. Seat belts provide an outside force that slows down/or stops your body by decreasing the force of impact that could injury/kill you.