1. The problem statement, all variables and given/known data hi all, Given: a car is reversing at 4km/h, weight = 1500kg... n whamps into a lamp post. i'm suppose to calculate the bending of the bumper, which is made of AlZn4,5Mg1 material. bumper is 900mm long n fix onto the car body dimension : 80x80mm U profile with a 5mm thickness 2. Relevant equations 3. The attempt at a solution i assume that we should use the kinetic energy formula which is E = 1/2mv2 to get the amount of initial energy. According to the law of conservation energy. initial energy = final energy = deformation energy/potential energy + sound energy(neglegible) + heat (neglegible ) from my what i've considered here, i guess i need a force F in order to calculate the bending distance of the bumper. but from the formulas i have above, how do i go about getting the force F which works on the bumper? the area underneath the stress strain diagramme of this material wouldnt help much because i couldnt really calculate (accurately) the area after the elasticity limit right?