safety belt in a car is used because
Seat belt A seat belt (also known as a seatbelt or safety belt) is a vehicle safety device designed to secure the occupant of a vehicle against harmful movement that may result during a collision or a sudden stop. A seat belt functions to reduce the likelihood of death or serious injury in a traffic collision by reducing the force of secondary impacts with interior strike hazards, by keeping occupants positioned correctly for maximum effectiveness of the airbag (if equipped) and by preventing occupants being ejected from the vehicle in a crash or if the vehicle rolls over.
Child safety seat Since the first car was manufactured and put on the market in the early 1900s, many modifications and adjustments have been implemented to protect those that drive and ride in motorized vehicles. Most restraints were put into place to protect adults without regard for young children. Though child seats were beginning to be manufactured in the early 1930s, their purpose was not the safety of children. The purpose was to act as booster seats to bring the child to a height easier for the driving parent to see them. It was not until 1962 that two designs with the purpose of protecting a child were developed independently.[5] British inventor Jean Ames created a rear-facing child seat with a Y-shaped strap similar to today's models.[6] American Leonard Rivkin, of Denver Colorado, designed a forward-facing seat with a metal frame to protect the child.[7] It is noted that seat belts for adults were not standard equipment in automobiles until the 1960s.