Pressure at a given surface is given as ratio of normal force and area
so here force due to heel of the shoes is given as 80 N
and the area of the heel is given as 16 cm^2
so we can say
[tex] P = \frac{F}{A}[/tex]
here we have
F = 80 N
[tex]A = 16 cm^2 = 16 * 10^{-4} m^2[/tex]
[tex]P = \frac{80}{16 * 10^{-4}}[/tex]
[tex]P = 5 * 10^4 N/m^2[/tex]
so pressure at the surface due to its heel will be 5 * 10^4 N/m^2
