SAT Subject Physics Practice Question 513: Answer and Explanation
14. A woman dancing in high-heeled shoes accidentally steps on her partner's foot with the heel of her shoe. Even though her partner outweighs her by 400N and can easily lift her off the floor, he feels pain because
A. her weight is concentrated into a small area.
B. her small foot has a large momentum.
C. her foot has a large inertia.
D. his foot has no inertia.
E. his foot has no momentum.
Correct Answer: A
The correct answer is (A). The pressure he feels is equal to force per unit area. His partner's heel is a tiny area, which bears most of her weight. This gives a large local force at the small end of her heel.