Well, common physics applies. The more mass an object carries, the more intertia. The more inertia, the less damage to said object. Think of it like a train hitting a bus, the train was not designed to implode when it hits something and yet, they tend to barely get a scratch when they are involved in an accident.

For a quick primer:

http://www.dmturner.org/Teacher/Library/4thText/EnergyPart2.html