Which empirical formula, expressed as y/n) (1 – a l/r), is used to determine the permissible stress in long columns?

Explanation

The formula y/n) (1 – a l/r) is commonly referred to as the Straight line formula, which is applied to calculate the allowable stress in long columns. Other options such as Parabolic, Perry’s, and Rankine’s formulas represent different approaches.