# Car crash impulse physics problem

1. Oct 29, 2008

### 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 Im still confused a bit

2. Oct 29, 2008

### rl.bhat

Re: Impulse

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