If she is standing still on both feet
area = 2 * pi d^2/4 = 7.95 in^2 total area of both feet
we spread 115 pounds over that area so
115/7.95 = 14.5 pounds/in^2
BUT
if she puts the whole 115 pounds on one foot (like walking) 7.95/2 = 3.98 in^2
115 / 3.98 = 28.9 pounds/in^2
A lady weighting 115 lbs is using a pair of high heel shoes. The area where the foot feels the most stress has a circular pattern with a diameter of 2.25 in. What is the stress exerted on one foot?
a. 28.9 lbs/in^2
b. 51.1 lbs/in^2
c. 57.8 lbs/in^2
d. 103.0 lbs/in^2
2 answers
just looking at the choices, the units are lbs/in^2, as in pounds over the area. area of circle=pi*r^2. pi=3.14. the diameter is 2.25, so the radius is 2.25/2=1.125. plug that into area of circle=pi*r^2=3.14*1.125^2=3.974.
115 pounds / 3.974in^2=28.9 lbs/in^2
115 pounds / 3.974in^2=28.9 lbs/in^2
1 answer