Chapter 20, Problem 29P

The mast of a sailboat has a cross-sectional area of 10.65 cm² and is constructed of an experimental aluminum alloy. Tests were performed to define the relationship between stress and strain. The test results are

Strain, cm/cm	0.0032	0.0045	0.0055	0.0016	0.0085	0.0005
Stress, ${\text{N/cm}}^{\text{2}}$	4970	5170	5500	3590	6900	1240

The stress caused by wind can be computed as $F/A_c$; where $F=$ force in the mast and $A_c=$ mast's cross-sectional area. This value can then $\Delta L=\text{strain}\times L$, where $L=$ the mast's length. If the wind force is 25,000 N, use these data to estimate the deflection of a 9-m mast.