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SHOW ALL WORK AND INTERMEDIATE STEPS. Before you calculate, breifly describe the

ID: 1385041 • Letter: S

Question

SHOW ALL WORK AND INTERMEDIATE STEPS. Before you calculate, breifly describe the concepts behind the math.

Consider a simple model of a free-standing dam, depicted in the diagram. Water of density p (lower case p in this problem represents the greek letter Ro while upper case P is pressure.) fills a reservoir behind the dam to a height h. Assume the width of the dam (the dimension pointing into the page) is w.

Consider a single horizontal layer of the dam wall of infinitesimal height dy. What is the magnitude dF of the force this layer exerts on the dam?

Explanation / Answer

a) Taking y to be the water depth measured from the reservoir floor, P=?gy. Since ?water?1, P?gy.


b) F=PA=gyA. A=width*height of water slice = w(dy). dF=(gyw)(dy)