Function spring_work 

pub fn spring_work(
    spring_constant: f64,
    initial_displacement: f64,
    final_displacement: f64,
) -> Option<f64>

Computes work done by an ideal spring force over a displacement interval.

Formula: W = 0.5 * k * (x_initial^2 - x_final^2)

Returns None when spring_constant is negative, when any input is not finite, or when the computed result is not finite.

Examples

use use_work::spring_work;

assert_eq!(spring_work(100.0, 0.5, 0.0), Some(12.5));
assert_eq!(spring_work(100.0, 0.0, 0.5), Some(-12.5));