Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Kinetic energy and crumple zones

  1. Feb 7, 2012 #1
    What happens to kinetic energy when the a car is impacted on the side of the crumple zone? Since the crumple zone is meant to absorb the energy from a direct front impacts.

    If one car was traveling west at 40mph and a second car going 40mph hit car one in the front quarter panel crush zone.

    What energy is transmitted into car one?

  2. jcsd
  3. Feb 8, 2012 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    2018 Award

    Energy is transferred to the car but since the crumple zone doesn't work the acceleration on the car is much greater than it would be if it hit from the front, as it will absorb the energy very quickly instead of spreading it out over time.
  4. Feb 8, 2012 #3


    User Avatar
    Homework Helper

    If the car is well designed, there is a possibility the nose section of the vehicle struck sideways will break off, and the kinetic energy will be carried away with it.

    remember the crumple zone if the whole front "rails and inner guards", so to hit them sideways means to run sideways into the front section of the car - in front of the fire-all.

    EDIT: the passenger cell of the car struck sideways will still accelerate sideways quite violently - and that is why we have "side curtain" air bags in modern cars.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook