The concept of pressure is demonstrated by lying on a bed of nails.
What it shows:
The lecturer (or someone else) lies on a bed-of-nails without discomfort, thus demonstrating the concept of pressure, which is the force per unit area. For added drama the person is sandwiched between two beds of nails with the added weight of a cinder block on top. The cinder block can be broken with a sledge hammer.
figure 1: A supermarket tabloid reports on how macho man pulls off this stunt.
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