PROBLEMS

$6\mathrm{.}6.$ The area shown is symmetrical about both the horizontal and vertical axes through the centroid. Each of the $10$ stringers has an area of $\backslash (0\mathrm{.}4\backslash$mathrm$\{$sq$\}\backslash$mathrm$\{$in$.\}\backslash ),$ and the webs carry no bending stresses. Find the shear flows in all webs by two methods, if the vertical shearing force is $\backslash (12,000\backslash$mathrm$\{$lb$\}\backslash ).$

$6\mathrm{.}7.$ Each of the five upper stringers has an area of $\backslash (0\mathrm{.}4\backslash$mathrm$\{$sq$\}\backslash$mathrm$\{$in$.\}\backslash ),$ five lower stringers has an area of $\backslash (0\mathrm{.}8\backslash$mathrm$\{$sq$\}\backslash$mathrm$\{$in$\}\backslash ).$ two methods, if the vertical shearing force is $\backslash (12,000\backslash$mathrm$\{$lb$\}\backslash ).$ Note that the cross section is not symmetrical about a horizontal axis and that it is necessary to find the centroid of the area.