Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?

The impact force will be same for both the cases.

Explanation:

The rate of change of momentum is known as the Impulse and is given by:

where

I = Impulse

Now,

In first case both the cars are identical and have same velocity and in the second case, the wall is stationary.

Also, in both the cases the car does not bounces off the things it hit.

Thus

Thus

Impact force,

Therefore, impact force is same for both the cases.

the answer is to check all of them! they all apply well at least i think so!

1/0.14nm = 10^10/1.4 a lot