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Message: <blockquote data-quote="pemerton" data-source="post: 8285176" data-attributes="member: 42582">You've calculated the static pressure: weight = 170 lb X 1,000 cu feet = 170,000 lb; pressure in psi = 170,000/ 14,400 [the surface area, in sq inches, of the block] = approx 12 psi as you say.In this trap, though, it is the impulse pressure that seems relevant (qv: I might be able to balance a rock or brick on my head without being squashed; but drop that rock or brick on my head from a balcony and it might kill me!).Impulse = change in velocity * mass / time of deceleration. Upthread we've established that the velocity of the block at impact is around 8 metres per second. The impact brings it to a stop. The mass in kg is around 77,000 kg. Let's say the deceleration happens over one tenth of a second (in "reality" it probably wouldn't be uniform; I've chosen this figure by Googling some collision web pages and using a generously long figure compared to actual collisions). Then we get impulse = 8 * 77,000 / 0.1 = 6,160,000 N. With a surface area of around 9 sq metres, we get a pressure of around 684,000 Pa. That's about 100 psi.The more rapid the deceleration the greater the pressure. I don't know what sort of pressure is going to be necessary to splat a Cube. The spongier the Cube and the more deformation it can handle, I guess the greater the deceleration time and thus the less the pressure the Cube suffers. My attempt to Google up the physical properties of jellies wasn't very successful (the webpages and papers that came up weren't ones I could interpret for the purposes of this discussion); so I don't know what a "realistic" set of figures is for a Gelatinous Cube.</blockquote>

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