system
Given the following post, respond as if you're commenting on Reddit:
human
[Iron Man 2] How does the Briefcase Armor have enough protection?

Using some simple math, I guesstimated it holds 2,500 to 3,000 cube inches of metal, and that's on the big side. The average human has a surface area of 2,300 square inches, and that's on the small side. If you just covered him in metal, nothing else, you'd have 1 inch of metal around him, but there's obviously many overlapping parts, so how does this thing protect him?
gpt
The Mark V is the weakest/flimsiest of his armors. It's there purely for emergencies. He probably doesn't even have a full one inch around in all places, as most of his systems are knocked out. What he does have are weak repulsors and an AI system. No flight, no other weapons, just some slight strength enhancements, JARVIS, and repulsors.

Vanko tore the suit apart fairly easily, if you'll notice. It's probably bullet resistant, but Stark obviously only meant it for emergencies when he couldn't access any of his superior models.