Chapter 4, Problem 8Q

(Indicates a review question, which means it requires only a basic understanding of the material to answer. Questions without this designation typically require integrating or extending the concepts presented thus far.)

Why is it that a person can lie still on a "bed" of nails (Figure 4.53) without suffering any serious injuries but would incur severe puncture wounds to his feet if he tried to stand barefoot on the same "bed"?