Mechanics of Materials question Two 12 by 1in plates are riv

Mechanics of Materials question.

Two 12 by 1-in. plates are riveted to a 12 I 31.8 section (see Fig. P7-5) for use as a 30-ft column. Determine the slenderness ratio.

Solution

slenderness ratio

lamda= effective length/square root of (I_X/A)

effective length is 30 ft= 914.4 cm

area which is 35.13 square inch = 226.644 square centimeter from table

moment of interia = 3010.8 in⁴ = 123410 cm⁴ from table

slenderness ratio = 914.4/square root 0f (123410/226.644) = 1.67