Two part question

Question

PART ONE

How much pressure is applied to the ground by a 66 kg man who is standing on square stilts that measure 0.05 m on each edge? Answer in units of Pa.

PART TWO

What is this pressure in pounds per square inch? Answer in units of lb/in2 .

Answer 1

P = F/A

F = mg = (66)(9.8) = 646.8 N

A = 2(0.5)(0.5) = 0.5 m²

P = 646.8/0.5 = 1293.6 Pa

Round to 2 sig figs

P = 1300 Pa

To convert to psi:

646.8 N x (1 lb)/(4.448 N) = 145.4 pounds

0.5 m² x (39.37 inches)²/(1 meter)² = (0.5)(1550) = 775 in²

P = (145.4)/(775) = 0.19 lb/in²