Safety Features of Cars (WJEC GCSE Science (Double Award)): Revision Note

Safety Features of Cars

• Cars today are designed to rigorous safety standards to reduce the chance of a severe injury in the event of a collision

• In your exam you need to know about the following safety features built into cars:

  • Seat belts

  • Crumple zones

  • Airbags

• Each feature is designed to increase the distance over which the energy of the passenger is transferred

  • This reduces the impact force on the passengers and the severity of their injuries

• The force applied to a passenger in a collision can be calculated using a rearranged form of the work done equation:

• Where:

  • Force is the force applied to the passenger by the impact of the collision (N)

  • Work done is the work done by the safety device to reduce the movement of the passenger (J)

  • Distance is the distance moved by the passenger as a result of the collision (m)

Car Safety Features

The seat belt, airbag and crumple zones help reduce the risk of injury to a passenger by increasing the distance over which the collision takes place

• Seat belts

  • These are designed to stop a passenger from colliding with the interior of a vehicle by keeping them fixed to their seat in an abrupt stop

  • They are designed to stretch slightly to increase the distance the person moves in a collision

• Airbags

  • These are deployed at the front on the dashboard and steering wheel when a collision occurs

  • They act as a soft cushion to prevent injury on the passenger when they are thrown forward upon impact

• Crumple zones

  • These are designed into the exterior of vehicles

  • They are at the front and back and are designed to crush or crumple in a controlled way in a collision

  • This is why vehicles after a collision look more heavily damaged than expected, even for relatively small collisions

  • The crumple zones increase distance over which the collision takes place