Inertia

When your vehicle in in a collision, your car stops, but you keep going. The video above is from an occupant simulator program. It graphically shows the motion of a passenger when the vehicle she was traveling in collided with a concrete barrier. The car was traveling at 30 mph and she had seatbelts on. Impacting a solid barrier at 30 mph is like being dropped from a three story building and hitting the ground. If you look look closely at the passenger she continues moving forward untill the seatbelts stop her torso. Her Inertia kept her moving forward untill the seat belt and car interior stopped her forward movement. Her arm impacted the dash broke. She was also seriously injured by the seatbelts force on her neck and chest. Had the vehicle been equiped with a passenger airbag her injuries would have been less severe.