Is Lower Impulse Better for Surviving a Car Crash?

[Slacker142]

I just need some quick input.

When dealing with impulse and say a car crash, would you want to have a larger impulse and thus a larger change in momentum or a smaller impulse and smaller change in momentum?

It seems to me that with a car going say 50 km/hr with a mass of 1000kg then your start momentum is 50,000 Ns. Then the car hits a brick wall and comes to a complete stop, its final velocity is 0 and its final momentum is 0 therefore its impulse being 50,000 Ns.

But then say the car hits one of those rebounder barrier type things with the same initial momentum but then ends going in the reverse direction at 25 km/hr. The impulse being 25,000 Ns?

So then its better to have a lower impulse in regards to surviving the crash?

I may have answered my own question but I am still confused a bit

 

[rl.bhat]

Impulse is a vector quantity. In that case what will be the change in the impulse in the second case?

 

[thomate1]

I can understand your confusion. The concept of impulse in a car crash can be complex and it is important to consider all factors.

Firstly, it is important to note that impulse is directly related to the change in momentum. In a car crash scenario, the change in momentum is determined by the initial velocity of the car and the mass of the car. So, in your example, the initial momentum is 50,000 Ns because the car is traveling at 50 km/hr with a mass of 1000kg.

Now, when the car hits a brick wall and comes to a complete stop, the change in momentum is 50,000 Ns. This means that the impulse is also 50,000 Ns.

On the other hand, if the car hits a rebounder barrier and ends up going in the reverse direction at 25 km/hr, the change in momentum is only 25,000 Ns and the impulse is also 25,000 Ns.

So, in terms of surviving the crash, it is better to have a lower impulse. This means that the change in momentum is smaller, reducing the force of impact on the car and its occupants. However, it is also important to consider other factors such as the design and structure of the car, the placement and effectiveness of safety features like airbags and seatbelts, and the speed and angle of impact.

In conclusion, a lower impulse may be preferable in terms of survival, but it is just one aspect to consider in a car crash scenario. It is important to consider all factors and make informed decisions when it comes to car safety.