When we discuss impact, we explore the elasticity of the object. Simply put and common sense dictates that a stiff object is more likely to deform upon impact that a soft object. Viewed from a conservation of energy perspective, the kinetic energy of the projectile is changed into heat and sound energy as a result of the deformations and vibrations induced in the struck object. However, these deformations and vibrations cannot occur instantaneously. A high-velocity collision (an impact) does not provide sufficient time for these deformations and vibrations to occur. Thus, the struck material behaves as if it were more brittle than it would otherwise be, and the majority of the applied force goes into fracturing the material.
When vehicles collide, the damage is proportionate to the relative velocity of the vehicles, the damage increasing as the square of the velocity since it is the impact kinetic energy (1/2 mv2) which is the variable of importance. Much design effort is made to improve the impact resistance of cars so as to minimize user injury. It can be achieved in several ways: by enclosing the driver and passengers in a safety cell for example. The cell is reinforced so it will survive in high speed crashes and protect the users. Parts of the body shell outside the cell are designed to crumple progressively, absorbing most of the kinetic energy which must be dissipated by the impact.
These same principles can be applied to packaging for freight as well as shock and impact created in equipment and appliances. The weight, velocity and inelasticity of the object(s) determine the amount of kinetic energy that must be displaced. This energy is displaced by introducing materials whose density and elasticity will absorb enough of the kinetic energy to prevent fracturing.