Function normal_stress 

pub fn normal_stress(force: f64, area: f64) -> Option<f64>

Computes normal stress from applied force and cross-sectional area.

Formula: σ = F / A.

Returns None when area is less than or equal to zero or when any input or result is not finite.

Examples

use use_elasticity::normal_stress;

assert_eq!(normal_stress(100.0, 2.0), Some(50.0));