COLUMNS AND STRUTS 45 



412. Calculate the breaking load for a wrought-iron column with 

 fixed ends, 9x4 inches section area and 20 feet long. 



413. Find the loads to rupture a round wrought-iron and a round 

 cast-iron column each 9 feet in length and 6 inches in diameter, with 

 flat ends. 



414. Determine the buckling load for a cast-iron strut with rounded 

 ends, 2x1 inches section area and 16 inches long. 



415. Find the breaking load for a cylindrical strut of wrought-iron, 

 3 inches in diameter and 10 feet long, with rounded ends. 



416. What load can be sustained by a cast-iron column with flat 

 ends, 14 feet long and 6 inches in diameter, with a factor of safety 

 of 8? 



417. A wooden stick 3x4 inches cross-section and 10 feet long is 

 used as a column with flat ends. Find the factor of safety under a 

 load of 2000 pounds. 



418. Determine the load for a fixed-end timber column, 3x4 inches 

 cross-section and 10 feet long, for a factor of safety of 10. What would 

 it be for a length of less than 2 feet ? 



419. Find the breaking load for a hollow cast-iron pillar with fixed 

 ends, 9 feet in length and 6 inches square, the metal being 1 inch thick. 



420. Find the safe steady load for a hollow cast-iron column with 

 fixed ends, outside dimensions 8x6 inches, inside dimensions 6x4 

 inches, and 10 feet long. 



421. Solve Problem 420 for a length of 20 feet. 



422. Find the safe steady load for a hollow cast-iron column with 

 fixed ends, length 20 feet, outside dimensions 4x5 inches, inside 

 dimensions 3x4 inches. 



423. Solve Problem 422 for a length less than 3 feet. 



424. A hollow wooden column of rectangular section, 4x5 inches 

 outside dimensions, 3x4 inches inside dimensions, has fixed ends 

 and a length of 16 feet. Find the factor of safety for an axial load 

 of 1200 pounds. 



425. A wrought-iron pipe 10 feet long, 4 inches external and 3 inches 

 internal diameter, sustains a load of 14 tons. What is the factor of 

 safety ? 



426. What safe steady load will a hollow cast-iron column with flat 

 ends support if it is 14 feet long, outside diameter 10 inches and inside 



