posted by ashey .
In a classroom demonstration, a 790-N
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.
a) What is the average force exerted by each nail on the professor's body?
b) 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) just divide 790N by 1950 nails to get the force in N/nail
(b) Now just change the number of nails to total area to get the pressure in N/m^2