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Science

Crumple zones

Moving cars have kinetic energy, which is changed into heat energy when they brake. Safety features in modern cars, such as seat belts and crumple zones, are designed to absorb kinetic energy in a crash.

Car safety features

Moving cars have kinetic energy. As energy cannot be created or destroyed, when a car brakes its kinetic energy changes into heat energy. The brakes heat up and then transfer the energy to the surroundings. Modern cars also have safety features that absorb kinetic energy in collisions. These typically include:

  • seat belts
  • air bags
  • crumple zones

All these features reduce injuries to the people in the car by absorbing energy when they change shape.

Car crash simulation

Car crash simulation

As they deform they increase the amount of time the person takes to come to a stop. This reduces the acceleration and force on the person, so reducing injury.

Seat belts have to be replaced after a crash because the large forces may damage them.

Other safety features

These are designed to help you survive a crash with as little injury as possible, or avoid a crash altogether. They include:

  • Anti-lock braking system (ABS) – prevents skidding allowing the driver to remain in control. The vehicle stops more quickly as there's more friction between the road and tyres.
  • Traction control - prevents skidding while accelerating so the car can quickly escape a dangerous situation.
  • Safety cage – strengthens the cabin section to protect people in a roll-over accident.

There are other features designed to help prevent accidents by reducing distractions while driving. They include:

  • Electric windows – make it easier to open and close windows
  • Cruise control – helps reduce accidental speeding
  • Paddle shift controls – allows the driver to keep both hands on the steering wheel while changing gear or radio stations
  • Adjustable seats – makes the driver more comfortable

Back to Forces for transport index

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