In a Classroom Demonstration, a 79

question 28

Multiple Choice

In a classroom demonstration, a 79.2-kg physics professor lies on a "bed of nails." The bed consists of a large number of evenly spaced, relatively sharp nails mounted in a board so that the points extend vertically outward from the board. While the professor is lying down, approximately 1950 nails make contact with his body.
-If the area of contact at the head of each nail is 1.26 × 10^-6 m², what is the average pressure at each contact?

• A)1.58 × 10⁵ Pa
• B)1.27 × 10⁶ Pa
• C)2.40 × 10⁴ Pa
• D)4.82 × 10⁴ Pa
• E)3.16 × 10⁵ Pa