How Does a Longer Crumple Zone Affect Impact Duration and Passenger Safety?

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A longer crumple zone in a car can increase the duration of impact, which affects passenger safety by reducing the force experienced during a collision. In the scenario presented, a car weighing 1980 kg collides with a wall at 13 m/s, resulting in a force of 3217.5 N upon impact. The method to find the new model's acceleration using F=ma and kinematics is confirmed to be correct, leading to an increased impact duration of 8 seconds. The impulse on the car and its passengers remains unchanged, as it is determined by the initial momentum of the vehicle. Overall, the discussions affirm that longer crumple zones enhance safety without altering the impulse experienced.
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question states: a 1980 kg car moving at 13 m/s is brought to a stop in 2 seconds when it collides with a wall. if a new model of this car has a longer crumple zone, the passengers experience a 3217.5 N force upon impact. by what percentage has the period of impact been increased? has the impulse on the car and its passengers changed.

my attempt at this problem is to find the new model's acceleration by use F=ma, then use the kinematics Vf=Vo+at to find the period to be 8 sec. Then I can calculate the percentage by dividing the difference with the original period. But this somehow seemed to easy and I am not sure if it's right. Also, I would assume the impulse doesn't change since P=mv, but I am not sure on this.
 
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welcome to pf!

hi milkyway11! welcome to pf! :wink:

yes, your method looks fine (and yes, the impulse doesn't change) :smile:
 


Thank you!

tiny-tim said:
hi milkyway11! welcome to pf! :wink:

yes, your method looks fine (and yes, the impulse doesn't change) :smile:
 

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