Damage From an Evil Vending Machine

[sir-talen]

So I'm trying to set up a simple opponent of a group of newbie GURPS players in a post-apocalypse game, and what I decided to use was a gang of berserk mobile vending machines, determined to provide "free samples" (ie: hurling cans of soda) at their victims.

So my question is: How much damage would a 16 oz can of 1,000 year old soda flung out at about 60 mph do if it hits a character? And what kind DX penalty would a character face trying to catch a can of soda? If a PC can successfully catch one of the free samples (alternating fire between the soda cans, hot cups of coffee, and harmless but stale muffins), the vending machines will cease their attack and back off.