Average crush force exerted on a car

[Mathbather]

Homework Statement

Homework Equations

Kinetic energy = Ke = (1/2)(mv^2) (joules - J)
where m = mass (kg)
v = velocity (m/s)

The Attempt at a Solution

What I was thinking was that the kinetic energy is divided uniformly over the distance d and hence
Average crush force = mv^2 / 2d

But I don't know how to prove that. Of course I could try to explain it with words, but I don't feel that it is enough.

Thank you in advance.

 

[Delphi51]

All of the KE is converted to work in crushing things: W = Fd = 1/2*m*v^2

 

[Mathbather]

thank you, very helpful!